Sonic Forces came out about a month ago and it's gotten some very mediocre reviews and I think that we are at the point where the boost style of gameplay should be abandoned for good. (Not saying they are bad, I'm just saying it's becoming an over-milked concept) I'm afraid that if they do another boost title it'll be a critical disaster.
Sonic 06 came out 11 years ago and that was the last game to incorporate elements from the Adventure titles and I think that it should be given another shot, just like with Sonic Mania. Speaking of Mania maybe they can do what they did with Sonic Mania and get a bunch of people who know the Adventure games like the back of their hands and get them to work on their own project.
The Adventure games are what defined Sonic as a 3D platformer rather than the boost titles which most platforming is done in the 2D perspective.
Only time will tell if this becomes a reality and if it does I know that I will be happy.
(Btw I'm Bill Dozer from YouTube https://www.youtube.com/channel/UCylrOl ... G2SYvgcYzw)