So to be clear this is not so much "Gamefreak is killing bank in a few years" as it is "the 3DS is dead and it is very possible all service dies within a few years"And let me remind everyone that when that happens it's going to cause 2 (possibly 3) "generation lockouts":
Can't transfer up Pokemon from Gen III-V (RSE, FRLG, DPPl, HGSS, BW, B2W2) to Gen VI (XY & ORAS).
Can't transfer up Pokemon from Gen VI to Gen VII (SM & USUM).
And if you can't send Pokemon directly from Gen VII to HOME that would be a 3rd lockout.
And remember GF's excuse for doing this (and not having ANY way for the games to interact between each) was a "future proofing" plan where Bank will always be the "go-to" app for your transferring need. And that lasted all for 2 years but GF is like a child inventor who makes something and claims big plans with it but soon gets bored of it and discards it for something new. Only hope to prevent a generation lockout is if they make it so Bank directly transfers a Pokemon to HOME. Of course that means you can't transfer a Pokemon from Gen V to VI or VI to VII but, to be fair, the only reason you'd play a past game is for the novelty of it and/or experience what it had to offer (and there's always hacks, especially for the games that can connect via Wifi and using an app that lets you spoof Pokemon).
Now, that is me at my most pessimistic I'll admit. The Wii & DS wi-fi services were shut down I think in due part to the servers not being theirs and THAT service shutting down (gamespot? gamefly? i dunno, something like that). The "Nintendo Network", used from the 3DS-on, is in-house and in theory could be run for even longer and have no reason to shut down until they do a full overhaul of the system. That could be years, dare I say, even decades!
But it's also possible they just pull the plug on the Wii U & 3DS soon because they're dead services just sitting there not bringing much to the table. And if that happens, then it doesn't matter what gamefreak hoped for, the Bank will be locked out. It needs the wi-fi service to connect your NN account and to the gamefreak cloud servers where all the storage is. There will be no way to dump anything from a gen 7 game into Home because it literally cannot communicate with it. 3DS isn't really built to communicate with Phones*, either, much less the switch. Even if gen 6 & 7 could communicate with each other ala the Pal Park or PokeTransfer, 7 would be the end point.
*I am convinced Nintendo tried at one point, though. In New Leaf's Welcome Amiibo update, it had a new system where you could earn tickets but the way the ticket menu was set up implied it was going to let you grab from multiple sources. Which would makes sense if it could somehow tie into the then-upcoming Mobile game; but nothing ever came of it. The fact gen 7 had a "Go" symbol and strings about recieving pokemon from Go makes me think gamefreak thought about it as well.
But I'm glad you talked about items because it is insane how they have never implemented an item trading tool. Like...why not? There's lots of valuable items, many one-offs, why not just cut the pokemon-holding middlemen and let us swap them directly? And also, let us transfer items through POkemon Home, you cowards???