Is Sage canon to GP?
I honestly haven't really fully decided on how any of the Frontiers stuff is gonna fit into the GP lore yet, all I do know is that those “The Ancients” guys are not just gonna all be basically just Chaos and instead they’ll be Mobians since if you guys remember, the Mobians in GP are vastly different than in most Sonic things (they're literally just weird psychic aliens that basically all went extinct in GP lore, the funny animal people are the Faunoids which are actually the direct descendants of the Mobians.), so if anything the GP!Ancients would probably look more similar to GP!Silver (albeit much less fluffy than my beloved Boi) than Chaos. Anyway as for Sage I genuinely don’t know what I’m gonna do with her as of now, but I can imagine her going through a phase where she realizes her “Father” Eggman is a narcissistic piece of shit who doesn’t truly love her and she decides to rebel and either succeeds and finds a better life for herself or she dies/suffers a fate worse than death (this is not me throwing shade at Sage BTW Eggman is just that cruel to those who rebel against him).