There is nothing stopping you from doing this. But they will only persist as long as that specific VM exists. e.g. if you copy this one to catalog, the resulting VM will not have the same affinity rule.
So yes it's possible, but it might be best to use some sort of automation to perform the task to 'remember' them if you happen to have more than 1-2.
I know people have done this to save on OS/Application license fees. The only caveat to be aware of is that entering maintenance mode could violate the DRS rule.