I am not sure how a continuation of the 90s era X-Men would work, would they use the same animation style, the same group of voice actors from Toronto (I do not think Lenore Zann does much voice acting nowadays, she seems to be successfully Canadian politician), pick up where the animated series left off? This seems an odd choice, but hey we have had some Timm style cartoons lately, so 90s nostalgia is a thing now.
Yeah, John Colicos, the guy who played Apoclaypse in the first 4 seasons (he also played Kor the Klingon in Star Trek TOS and Deep Space 9) is dead, James Blendick who played Apocalypse in season 5, still seems to be alive (and does sound close to Colicos).