Call me fake; I really don't care. This is secondhand information of someone's interpretation of what they've seen anyway.
There are new types of regional forms. I do not know the exact name of these two.
The two versions have a very distinct difference in these forms. Some are obtainable in both versions but it is clear that each favors one version.

Scarlet will have ancient forms. These are going to be very remnisant of hisui forms. Pokemon from long ago now extinct or thought to be extinct. The professor in this version will be responsible for studying these Pokemon.
The professor in Violet will have more futuristic Pokemon. As their point of study. They are Pokemon genetically accelerated. These will not require a futuristic look to them, just an "enhanced" version of the Pokemon although many of them do have a futuristic theme.
This brings us to our legendary Pokemon. One is very genetically stable, almost the same stability of a Relicanth. The other, genetically unstable and continuously changing.

Diglet, seviper evo, venomoth, sunflora, greninja will receive a futuristic form.

Spinda, zangoose evo, parasect, charizard, Persian get ancient forms.

I am unsure which of the form types Tauros and dunsparce are or even if they are evos.

New evolutions for eevee are in the game and obtainable in both versions but are actually different forms of old evolutions. They too follow this past and future theme.

I will answer questions if I see them but I only know so much.