Yeah, boo fuckity hoo. You don't get to murder 200,000 Americans than say "time out, I have the Kung Flu, you're not allowed to compaign against me".
Biden needs to continue pointing out Trump's shitty record without specifically calling him out for being sick. Everything else is fair game. I don't think there's a clause in the Constitution for a time out.
Besides, again, for all we know the real test will come back negative and he'll be back to swaggering and lying in a couple days.