Unfortunately, this is very likely to be true, with rising pandemic impacts.
I suspect this will carry on through Spring and next Fall will be very busy. CB/ACT need to be ready to add multiple test dates as they did this year.
Maybe (just maybe) May or June will be a bit better.
I’m very glad my D wrapped up standardized testing in November as a Junior, the day before our school district shut down in-person classes and went back to remote.