No. If it were a mainline SMT, or even a side game Persona like PQ, perhaps I would've thought differently. If anything, a late Switch port of Trails of Cold Steel III seems more plausible.
Isn't Cold Steel III still being made with Phyre engine?
Considering it's a Sony thing that would be very troublesome to port the game on Switch, and Falcom aren't the kind to bother with that (on top of what was said about their audience)
Regarding Persona 5 I honestly don't see why they wouldn't do a portable version again, while very unlikely I'd still say that there's a small chance for a PSV SKU but they took too much time to release the console version and PSV being an inferior hardware (on the technical side) would probably make it a bit harder than it should be.
So if it had to happen on Vita it would need to happen quickly, and that doesn't fit with the technical struggles they would encounter while trying to do so (unless they planned it way ahead which is not impossible but again very unlikely)
Switch is a definitive option, though not an easy one either, Persona 5 is originally a PS3 game that had to be ported to PS4, at its core it was developed on a very different system than Switch, porting the PS3 SKU and upgrading it might sound clever since Switch is more "powerful" than PS3 but it is not because of the very different hardware architecture.
Downporting the PS4 SKU is probably the option to choose, but it's not as easy as a copy/paste make the resolution 900/720p and call it a day, there are still a lot of optimization tasks that need to be done.
There's also the cost/opportunity of going forward with the Persona team on Persona 6 instead, using the knowhows acquired with P5 but even for that you'll have to wonder if they'll go PS4 exclusive or go PS4/Switch.
SMT HD might be a game where they learn on the technical side how hard it is and if the knowledge can be easily translated to another project , while not as impactful the Fantasy RPG project is also taking a few ressources here and there.
As I see it an Atlus roadmap for their "HD" projects in the coming years could look like this
Q2 2018 : SMT HD on Switch or Switch/PS4
Q4 2018 : Persona 5 Switch
Q2 2019 : Persona 6 on PS4 and eventually Switch depending on both the business and technical side
2020 : New fantasy JRPG on PS4 maybe Switch but i'd say it's less likely than above.