A few days ago, Terry J. Reedy created the issue about the formatter module.
The issue is mainly about testing code but also discussing the removal of the module.
I noticed that the formatter module was deprecated in 3.4 and it was originally scheduled to be removed in 3.6. But the removal was delayed until 2.7 EOL.
Now 2.7 is EOL and there is no usage in stdlib.
So IMHO, it is good to remove the formatter module in 3.10
So before removing it, I would like to hear the concern.