No they are not (yet).
Metabo already started the CAS years ago and it's steadily growing. With a lot of (unknown) companies following.
And Fein goes to Bosch CSP batteries at the end of 2022. Other brands like Brennenstuhl, COX, Lena Lighting, Klauke, Sonlux, Wagner, Ledlenser already followed.
So maybe Festool changes in the future?
It should make the use of other battery tools a lot easier.