Not necessarily. If either of those owned receivers were used in a guest room that it only used occasionally, the TS might want the ability to activate & deactivate it based on whether guests were coming or not. I've been considering trying to get a couple of owned receivers to put into my upstairs guest rooms. If I did that, and DirecTV then forced me to upgrade them, I'd be pissed if they put me onto a leased model, which would require me to either keep them active all year long or return them every time that I wanted to deactivate them (and worse yet, charge me and trigger a new 2 year commitment every time that I wanted to reactivate them).
But someday, those receivers will become obsolete. Maybe not for many years, but someday. Then Directv can tell you "these are no longer compatible with our system, they must be replaced" and they'll replace them with leased receivers. That's the risk you take with owning, that one day what you paid for and own will become worthless.