Well I was on a modding team for over 3 years and have been waist deep in the modding community for the better part of a decade.  So I know from research and the murmurings around the community that the Special Edition is flat out superior not just visually but in terms of stability and optimization.  

I think it's the special edition, but ported so probably compromised a bit for the Switch

Predicting 360 version.

Either the last gen versions or its own version that is somewhere in between Special Edition and last gen.

It's almost certainly the new version downgraded for Switch. It wouldn't make sense to port the old version since the new one is supposedly much better and downgrading it shouldn't take too much of an effort.

I honestly have no idea why people keep suggesting it has to be one or the other. It's not like tweaking a few things is going to require much effort, it's porting the whole thing that's the big deal. Compared to that, tweaking a few settings is nothing.

I say it will be somewhere in between the 7th gen and 8th gen version. Probably 8th gen with some tweaks to make it work with the Switch

Looks like somewhere in the middle, which will be awesome for on the go. I held off on buying SE for the opportunity to replay it anywhere. Day one buy for me!

Maybe liké most multiplatforms games on Switch from 3rd party itll bé thé Old génération version

If it's special edition, they would just mention somewhere in the title.

What games are old generation ones? I can only think of Skyrim.