This is extremely unlikely, and if it were to happen it is for an extremely small time. I have never heard of this being a practical concern.

Half a millisecond of occlusion is enough to cause problems?

Depends on the telescope, but yes.

I thought most 'real' telescope exposures were over minutes to hours?

What happens from birds, soot, bugs, airplanes, frisbees, and clouds?

They don't emit giant amounts of EMR.

Also, almost all of those serious observatory telescopes don't have to worry about. Which is what we are talking about.

I'd love to read an article on how Frisbees are the biggest threat to observing the universe :D

Could describe what such a problem would be in layman's terms?

Terrestrial telescopes, which we've invested a bunch of money in terms of observatories in, receive interference from Starlink satellites. Telescopes in space, like the Hubble, don't have the same problem, but they're on the magnitude of 100x more expensive and its difficult to have the same missions.

Noting that the orders of magnitude increase in cost are directly caused by infrequent launches by launch systems with tight mass and volume constraints, and the need to build a space telescope on the ground, have the equipment survive launch, and then survive with no intervention for a decade or two in space.

As new launch systems like Falcon 9, Starship, New Glenn and New Armstrong eliminate these constraints it will eventually be cheaper to build telescopes in space than on the ground.

Other “pusher” motivations include worsening access to real estate, reduced control over light pollution, recognition of indigenous rights, etc.