The trick here is that they describe internal loadshedding as quota limits.

There’s a quote for your general class of query, and there’s a quota for how many can be in flight on a given server. It’s not necessarily about you specifically.

This was the vibe I got, that they were actually just load shedding but writing it as a 429 with a message about the quota being hit. And if they need to load shed, fine, I get it, but it is a waste of time for me to go in circles trying to figure out wtf is wrong when they're just too cowardly to admit it because it might impact whatever SLA some PM has.

It just leaves a bad taste, and the second a competitor comes along that has an acceptable offering, then I'll move. Just ridiculous gaslighting behavior.