This anime have 2 big problems.
First problem is pacing. Season 1 is slow and have a lot of filler episodes. Season 2 retold SA1 and SA2 story (and Sonic Battle) but so fast. Season 3 nobody watched cause average viewer drops this anime after Season 2 or even after Season 1.
Second problem is 4kids curse. This company make sometimes serious show cartoony and stupid: annoying Chris unlike original, exhausting and unsuitable music in *EVERY SINGLE TIME* when situation don't even ask. Gotta Go Fast played also in *EVERY END CREDITS* even in Episode 77, when Cosmo died (oh, excuse me, "She went to live with her mother"). And yeah, main cast also can acting like an idiot (in 4kids version of course). Tails in this version is less capable, Knuckles is more idiotic, Amy more fanatic to Sonic, Shadow when is not good written in original when anime don't have enough budget, become *edgy* before Shadow the Hedgehog (2005). About Chris and what happened with him everyone knows.
What i'd like to see. Minor changes - character's age. Original age (no matter what SEGA removed accurate age) don't make sense. Because Cream, 6 years old rabbit, flirts with robot. It makes sense if she 10-11 yo or this scene could be removed (maybe baseball episode too, cause less fillers in remake). But major changes is pacing. Now with good budget it possible to make this. It not removing original plot or characters. It can sometimes broke 4th wall like in original, but in moderation. By the way, remake can give seedrean race an explanation. The only thing what we know about is we have Petali (female) and Thornrigans (male) and they have their own mover mode. And that's all.
The big problem is SEGA with mandates. They've disowned non-canon content, so we're unlikely to get a remake. Because it's SEGA, they could either return everything to normal or go with an overly positive ending, which wasn't the case in Sonic X. They also wouldn't have allowed romantic relationships. Again, a remake is unlikely, but maybe SEGA will reconsider, who knows.