This is where we differ, as I don't know your contacts or test experience.
I've either been part of, or have known about tests [some I haven't been able to discuss] and "to date" there is no sign of a DSWM LNB "in test", or has anyone said there are plans for residential use/testing.
Those that have been on the forum for some time are familiar with "soon", but a residential DSWM [LNB or not] hasn't even reached "soon" status.
You have the testing experience here, I have none with Directv. Nor do I have any contacts that would provide me any inside info on what they're planning. I'm just "speculating" as per the thread title based on what I observe/find, and what I know about design and manufacturing costs for ASICs similar to the DSWM. If you say there's nothing "soon" then if it is coming it is further away than however far out your information goes. IIRC you were involved in testing SWM, do you remember when SWM support first showed up in the receiver firmware? Was it in advance of when you even heard about SWM, or were early testers forced to use CE firmware because the NR firmware didn't even support it?
My hunch is that the timeline depends on RDBS/BSS. We know Directv has two satellites launching in the next year with full CONUS RDBS payloads. D14 is destined for 99, the orbital slot for D15 hasn't yet been made public, though most assume it will go to 103. Currently D12 is broadcasting four RDBS spots in the western US, but it isn't know (at least by me) what, if anything, this is used for. FWIW, the "single LO" patent shows reception of RDBS from 103 but not 99. That may not mean anything though, as they had a patent for a LNB that receives Ka from 101, but it turned out that band was never used for customer content.
So plenty of unknowns, but assuming RDBS will be used for customer content Directv will need to replace both the legacy and (almost certainly) the SWM LNB with updated models to be capable of receiving these new bands from 99 and/or 103. Perhaps the DSWM LNB that shows up in the firmware allows reception of RDBS from 103 for testing in the markets served by those four spot beams from D12. Maybe when they do RDBS "for real" it will use a DSWM LNB, but the customer base that requires RDBS reception will be small and can better support a slightly higher cost. For instance, if the content on 95* was replicated on RDBS, Directv would surely come out ahead installing a DSWM LNB rather than a second dish and an external SWM module. If it also replicates content from 119*, it would explain seeing a Slimline-3DS but not a 5DS as an option - as well as having only 14 input bands.
Perhaps RDBS will be used for 4K, which will initially be a rather small market, but Directv can charge those early adopters a "4K fee" or 4K install fee or whatever to easily defray the cost of a new LNB that may cost a few dollars more. If/when it gets bigger market penetration the DSWM ASIC could be shrunk to a smaller process and made less expensive if necessary. One of the moderators of the "other site" stated there will be a Genie HR54 and HR46, one being a lower cost version and the other being a model that supports 4K. Maybe the 4K one has 10 tuners and requires a DSWM to be used to its full capability, who knows?