He just. cannot. help. himself. If there was any question of whether he would get his shit together if he was elected (and why - how - could he?), it’s been firmly answered in the negative. It’s a very disturbing indicator, as we know he’ll do the same when an international situation is really serious, because he doesn’t seem to understand he’s president now.
The planes in question would be for the next president - it’s easy for Trump to say no to this when it doesn’t affect him. Even if he flew in his own plane at this point, I’m sure he’d make sure it had been fully retrofitted with all necessary security options, upgrades he’d keep when he left office…