Wanna improve the Sevii Islands?
No generation 2 pokemon, F that.
What you really want to do is add Kanto regional variants and retcon them as Seviian Island forms. Now thats what I call KINO.

I heard we're getting Lets Go Red & Lets Go Green. Remakes of Fire Red & Leaf Green. Much the similar I heard Gen 4 + evolutions wont be locked behind post game, with regional variants being renamed Seviian Forms. Your leak is pretty similar whose your source? If anything seems to be indicative of a Generation 1 game of some sort is in the pipe line.

Lets Go Red & Lets Go Green is coming.
Regional variants are being called Seviian forms.

It will be announced this month. Sevii Islands are in the game, regional variants are now "Seviian". Mt. Silver and Tohjo falls are in Kanto. Mew is on Birth Island.