Xoogler, had connection with people working on TPU.
AFAIK, TPU support on GCP has been started in 2018? Or earlier? It's been 4 years to GA.
Rumors have it that the project has been incredibly difficult to get out due to Googler's poor cross-org collaboration support. It has been a sad story, another one in the list of things that Google could have been putting more resources and made available sooner to the public.