I haven’t seen the rate limitation issue for a couple of months now. The issue is not new, IIRC the Aurora team needs to provide more and more anonymous accounts as the user base is growing. Some months ago we had this problem for more than two weeks. I just checked and Aurora finds no connection, but until today everything worked flawlessly. And I expect it to work again soon.
I feel your pain though. I am degoogled for more than 5 years now and what I learned is that Google will always look for ways to make our life harder. More and more basic functions such as network location were seperated from the AOSP into proprietary google services. I am pretty sure this will get even worse in the future.
We must not forget that we rely on open source software and a hand full if developers, everything can break tomorrow and we are fucked.