Hey, some people really dig boost-sonic, and that's why it's coming back after having been abolished in Lost world!
That being said, bringing back Boost Sonic is... probably to Sega's detriment given that 2016 brought us Indie proof of concept 3D Sonic Games like Green Hill Paradise and Sonic Utopia that attempted to set out and show that maybe boost sonicc is a biiit on the regressive side.
I also really like a fellow named BlazeHedgehog over in various communities' idea for 3D Sonic. he's someone who makes fangames... anyhow, he thinks a fun idea for 3D sonic that might work is if Sonic had say... car controls. make his controls for platforming and when you're not holding the 'gas' button feel Mario tight and such, but introduce an analogue shoulder button for the purpose of GRADUALLY bringing him up to higher speeds, and at that point forward nolonger wold have to be held, as he'd adopt a racing game control scheme, and THAT would fit amazingly into boost sonic level design quite nicely.
Sonic Generations got good critical reception, and there's quite a few folks who can go back to sonic unleashed and enjoy that game for what it is now. I don't think Sega can really AFFORD to try and reinvent the wheel again. at least... not until Sonic Mania comes out and weather that gets praised to high heaven or people bitch that it's pretty much a Romhack will prove if Sega is willing to extend the olive branch to the community further and maybe say... hire on the Sonic Utopia guys or the folks making Sonic World or... SOMETHING.
EDIT:
here's the gameplay, but direct captured.
A couple of things to note; White whisps are apparantly back, and sonic gets no energy nor does he free a animal when he destroyes these... really bland and generic looking eggpawns.
Actually, wait... the buzzbombers and the Death Egg Robots are also missing the usual flair Dr. Eggman puts into his work. he's normally a narcasist of sorts, and has a flair for the artistic in his robot designs (besides in Sonic06 where they conveniently replaced Dr. Eggman with a really bland and generic bald guy who looks nothing like teddy roosavelt wearing a Dr. Eggman cosplay)
so uh... either something has happened to the lovable goofball, or Sonic Team have no idea WTF they are doing and changed the designs of iconic enemies for exactly ZERO REASON