You mean Burton's OTL Batman style being usurped by OTL's Schumacher Batman style?
Very bad things critically, to be sure.
But there is the VHS market. What was the biggest budget movie of that era that was saved, commercially speaking, by home viewing?
If you mean the Dark Knight Trilogy and the DCEU version, nothing changes except more location shooting and less time in studio backlots, and possibly a less wacky score and soundtrack.
IMO you may then effectively get Batman '89 and whatever possible followup being in the style of--to cite arguably the two most Nolanesque directors from that time--Kathryn Bigelow's or Ridley Scott's 'NY/LA/Tokyo are Lawless Metropolises [Wot Need A New Kind of Sheriff Who Breaks All The Rules]' thrillers of the era (Cold Steel, Point Break, Black Rain and Someone To Watch Over Me?, respectively).
Everything changes.
Also, tangentially, here's some food for thought. Joel Schumacher's filmography,
https://en.wikipedia.org/wiki/Joel_Schumacher#Filmography
St Elmo's Fire is a damn good comedy/melodrama, it's close to the lowkey dramas that Scorcese and Coppola were doing in the eighties. I've heard good things about Lost Boys and Tigerland. Heh, Falling Down is a minor LA sunlit noir psychodrama classic, and dare I say... an antecedent to the new Joker?
What if
his post-Burton Batmans were radically different?