That's not true. The show does not have to air. It all depends on the Guide Data. In the case for Grimm, my DVR recorded even though Grimm had been pre-empted since the Guide Data hadn't changed.
By changing the episode title, the DVR believes it is a new episode and will record it.
I reject your version of reality and substitute my own, then, is it?
Merg, please understand that I have great respect for you and I consider you probably the smartest and most level-headed member of this forum, but I'm sorry; it just is not that simple. "That's not true" is an opinion, but also a sweeping statement with nothing evident so far to back it up other than your imagination. You are entitled to an opinion, as am I, but that is all either of them are without facts to back them up. I guess we could agree to disagree, but when things enter the realm of sweeping statements expected to be blindly swallowed whole, there has to be some attempt at accountability.
Whether we agree on that or not, here is my version of reality; I'm sorry that some things do not have shorter explanations, but sometimes understanding implies detail:
It may appear to you that repeat or first run status depends on the episode title or guide data because that status and what appears in the guide are usually choreographed to be in concert with each other. But status and guide data/ep title are actually two different things independent from one another. I can change my phone number and I can change my address, and changing one will not always imply a change of the other because they too, are two different things independent of each other. If I change my address I may not have to change my phone number, or I may, depending. But they are still two independent things.
I disagree that it depends on guide data; my understandint is that it depends instead on a metadata flag independent from guide data, and that is metadata that can be manipulated to get your DVR to see any program as having whatever run status they want it to have regardless of the title and regardless of whether it ever aired or not.
Mistakes with guide data out of sync with that metadata have listed programs that are first run as repeats, and vice versa. And whether they record or not depends not on the episode title at all, but on how the metadata flag might be set and how your particular DVR is programmed to handle it (first run, repeats, both) and whether or not it concurs with the 28-day rule. The episode title is absolutely irrelevant.
Having an episode scheduled, then pulled, renamed, then rescheduled would be the ideal opportunity for the provider to manipulate the metadata flag so that the show is tagged as first run regardless of the ep title, and that is also a case where my personal definition of first run coincides. Yours may not, but neither matters.
And you can't really have any idea how many times the guide data may have changed or may not have changed, because all you see is what is scheduled, which is merely a subset of the metadata. The only one who knows is the person who has the ability to change it. lots of metadata is not represented in what the customer gets to see in the EPG, and particulary not displayed is how many times it was changed, when it was changed, or if it was changed at all.
Every episode of every program has an unchanging unique identifier independent of the title, sort of like an ESN, or MAC address, or SS#. The DVR does not keep a record of the episode title for the purpose of determining run status, it instead keeps a record of the run status metadata flag associated with that identifier that each recorded show has and creates exception lists based on the DVR's local database of shows (by virtue of their unique identifiers) recorded and available and shows recorded but deleted in the past 28 days. Those "do record" and "don't record" exception lists are what the SL refers to when a potential recording opportunity arises.
The episode title and the metadata flag are typically in concert with each other, but they are two different things that can be manipulated independently when necessary; the metadata flag can be changed independently from the title, meaning that the title can change and your DVR may not record it because the metadata flag accidentally indicates it is a repeat, or the title may not change but the ep still may be recorded accidentally a second time if the metadata was not also changed.
A perfect example is Continuum. It aired first in Canada, yet the guide data indicated that it aired many months earlier than it aired on Syfy. But it still enjoyed first run status (and my DVR dutifully recorded it), regardless of whether it was considered a repeat in Canada due to the ep title or guide data, because the run status metadata flag was properly reset for first run in the USA. If manipulating the ep title were part of what determines the repeat status, then same-week second airings of Veep, Defiance, Justified, and probably hundreds of other uncounted cable shows throughout the week, would prevent those who missed the premiere airing from being able to automatically get the second airing. So that pretty much proves that relying on the ep title can not be the way that works.
What I said is that a show has to air to gain repeat status, meaning it has to air to become eligible for repeat status (not talking about an ep that typically repeats multiple times in the same week, which is still considered first run) and I stand by that, because in what world would it rightly be considered a repeat if it had never aired? When a show has aired, and finished its first run, typically only then is the metadata flag changed to reflect that it has the status of repeat or second run, depending on how closely repeats are scheduled. But that is typically managed manually, so mistakes can happen and when they do, all bets are off on whether it will record or not.
What NBC did with the title or guide data is irrelevant, and what they did with the run status metadata flag is totally relevant. Apparently they handled that correctly, because the ep recorded for users that had it in a SL.
Absolute facts? I have none, just like you. Accept the premise or don't. But working directly with these sorts of similar issues for decades, I know how these things work. And this version makes sense.