SCOTUS can of course overturn any statute for any reason, valid or not, subject to very few practical restrictions. So when we're talking about where they'll intervene, we're always doing that with the proviso that we're predicting their behavior based on their charter and their history.

Having said that, the history of 4A law suggests that the word "reasonable" in 4A connotes a mandate for unusual deference to the legislature --- and SCOTUS already tends strongly towards deference.