One more time.
If he actually says he is going to declare in terms that give any specifics, reason for the delay, date etc. then that statement itself become the declaration. There are some laws here that prevent all that. It would in essence void the reason for the delay which is primarily the equal time rule for the networks.
That is the reason we heard the statement from Wolf at Law and Order about no FDT episodes after the new season. No reason given, just the fact that he has left the show. To actually state directly that he left the show to run for president would imply declaration.
I wouldn’t think the equal time rule applies to non-political fictional works.