Generally shouldn't be a problem I'd say just make sure the game audio is still audible

It should be 100% fine, i.e in Dream's former wr 1.9-1.15 minecraft run. In that run he's in a call with a couple of his friends. Once again, you just need to be able to hear the game audio in the recording and you'll be fine.

Im curious on what made you think it wouldnt be allowed? :p

I remember when one of my World Records got beaten by a guy who casually took a phone call midway through his run.

Made me extra salty. The arrogance of not only beating my run, but fielding a call at the same time?!?!?!?!

(I joke - good on him for being that skillful lol)