No one wants to debut their major trailers on something like Medieval or anything that isnt going to open to at least 10 million (not counting indie/art)
Studios dont want Universals Hulk or She Hulk first trailer blacklash over unfinished fx
WB is kind of its own special animal with the chaos over their release dates. In general studios are waiting until they are relatively sure of release windows and if they are going streaming or not
Chains tend to remove trailers to cutdown turnaround times as other than something like Top Gun 2 studios stop caring after the first 2 weeks.
Trailers will ramp up again once Black Adam and Black Panther 2 and CCXP hit. Then die out a bit in January
Id imagine D23 will premiere the new Avatar 2 and at least one Marvel trailer with an outside chance of INDI5