PPP is really the only item which will make a big difference in halacha. Not whether or not some admins are not nice to some parents. That is just the PR of it.
Even with PPP, it's very possible that some schools will still be in the hole, due to reduced fundraising and tuition collections. So then what? If you take the approach that the parent body is still responsible for the overall financial health of the institution, then everyone should still be paying as much tuition as they are able, no? But if you take the approach of fee for service, then it shouldn't matter whether they got PPP - it's more a question of whether they're providing sufficient service to command the fee.