Unless it’s an embarrassing “I fell” syndrome incident I suspect they’d probably go to the one they know as they can probably pull strings and get better/quicker treatment

Whilst I agree on the glue records, DNSSEC is most definitely included as standard (check my domain itsg.host which is on a free account)

If you want a truly privacy respecting option (because self hosting), I’ve been using https://cactus.chat which is great. I specifically use it on my streaming setup as it’s real time as well to boot.