Without regular updates, I doubt someone would spend Robux on Legacy SSS.
For a free-to-play game, regular updates are needed to make players spend in-game currency.
I noticed some Roblox experiences can share/transfer content between one another. So I can imagine SSSLegacy can still have the original zones, gameplay and shops they had before while SSSReborn skins and chao can be carried over to SSSL to be used cosmetically.
They got to be careful with Sonic related thing, it could "awaken" the fanbase.
But if there is later, I wondered how they would design the girl represents Sonic franchise ... a furry girl?
That "awakening" could be what 404 RE:SET needs to assure a fair chunk of Sega's fans attention to this game.
And I don't imagine the anode and cathode versions of the Sonic franchise to look like Super Crown bimbos.
I imagine them more like...
Maybe the Cathode version being based on Shadow.