They are finally starting to. Oracle just announced a week or so ago that they're going to be introducing TPUs to their cloud next year for customers to use.
https://www.msn.com/en-us/technology/tech-companies/oracle-e...
Interesting times ahead with a number of chip makers now vying for this market. TPUs are a mature chip now which gives some strong advantage. At the same time as the TPU announcement, they also mentioned they'll be deploying Cerebras systems as well.