Trump is going to pretend and hint that he is running until the last minute . His ego loves the speculation and false hopes among his base.
When it comes down to it, it is lot les likely that he will do so.
For two reasons:
(1)His ego won’t be able to take it if he loses again
(2)He can’t risk the mainstream Republicans turning on him more than they already did. He doesn’t need any former Republican allies looking to get him out the way turning to Democrats with something they “remember” Trump told them that can cause him major legal trouble. There is just a limit to how far you can stretch the value of negative attention when your former allies turn on you.
The above assumes Trump is still capable of rational thought. I’m uncertain that is still the case.