We are Americans who spend several months a year in Paris and haven't been able to get this question answered. Hoping the answer is "yes"!
There are no plans to remove the mask requirement from public transportation anytime soon. The mask requirement for Paris Metro/RER/public transport was put in place on May 7, 2020 and there has been no updates about removing this requirement that I can find.
Currently the fine is 135€ for not wearing a mask if caught by controllers. There are people who disregard this rule though, hoping they won't run into RATP controllers.