Its crazy WBros are not doing legacy sequel movies
We kind of know why (cast spoke out against JK, so JK obviously ditched plans for legacy sequels and convinced the studio to do this reboot stream series instead, probably said Potter has to be based around them as kids, not adult versions )
But you'd think the studio would've doubled down and gone no it has to be legacy sequels with the original cast
A Harry Potter '9' (either based on Cursed Child or not) starring the original actors in their 30s with whoever left alive out of the adults (or AI/CG if necessary) would easily clear 2b worldwide maybe 3b , just think of all the millions of fans who were kids growing up on Potter novels/films in 00s who now have kids of their own showing them the movies on stream or 4k blu. it'd be The Force Awakens but bigger. and then potential further sequels could continue with Potters kids indefinitely (the OG actors all making at least 20m each per film)
I guess they could still do that after this new reboot but doesn't seem very likely atm