The idea of young avengers is fine tbh, regardless of if anyone asked for it. Black people didn't know what a Wakanda was until 2016 nor who Blade was prior to '98. Nor were comic fans asking for Blade back then, nor GotG a decade ago. My point is, caring what comic fans want is a double edged sword (bc a lot of them ain't shyt) and mainstream audiences are passive participants who go with the flow as long as it looks compelling.
The last point is where the real problem may lie tho, in that how compelling/well received are cassie, katie, riri, kamala, chavez, eli, etc? It was mentioned in another thread the lack of a hero's journey for at least a few of these characters, which may be skipping some important steps that had people feel compelled to follow tony, steve, thor, t'challa, peter, etc.