This trump covid thing probably isn’t a lie but will definitely turn into “its not so bad” thing. If the campaign manager was able to control Trump’s message, it would be a “it can be defeated” message. We know that isn’t happening.
There will be two outcomes:
He will be in serious condition or die, in which case he is very dumb for having downplayed it and is getting his just desserts.
OR
He will be fine, in which case it's very unlikely he had it in the first place and is probably lying.
And then from Trump's perspective it's:
He dies, in which case he cares very little for the messaging
OR
I beat it, it isn't that bad, we should open up, etc.
The "it is what it is" plain reading of him probably getting better from this and one individual case (no matter how high profile) not being a good reason to change any sort of policy on a grand scale will almost certainly not be given by either side.