That depends, I don't think that there needs to be anything emoji specific (at the character level). It could be a special handler for inline results, marketing filters, etc that's gated on some variation of that string.

Might be worth seeing if there's another "how many X on iOS" that faults as well, because I would be that it reports an ISE on timeouts, and you could easily imagine some service making a follow on request that now times out.