Hmm I'm just gonna copy paste the one I bought from them last year as it seems to fall within the range you're describing:
Samsung - 60" Class (60" Diag.) - LED - 2160p - Smart - 4K Ultra HD TV with High Dynamic Range
Anyway, I've not noticed this issue at all myself, and I have 4 consoles connected to it (including the Switch). The only time the TV flips for me is when I power up a console, and I actually rather liked that feature.
The Switch is actually rather cool in that when you dock it it will immediately power on the TV and flip the input over. This is a feature you can turn off in system settings, but I personally love it and it is easily the fastest launch-to-play console I've played in a few generations.
I'm sure there is a problem for some people, then, but it's due to the TV, not the Switch (I imagine they don't realize you can turn that setting off). I can attest from personal experience over the last six months that not all Samsung TV's from 2016 are guilty of this as well... this TV has been absolutely superb, my only complaint being that the damn remote is so tiny that I lose it all the time lol
Just to be clear, though, I'm sure this problem is definitely happening for people. After six months with my Samsung TV and 1 month with my Switch plugged in, though, it's not happening for me, so it must be more specific models than merely "2016".
