While everything is eagerly awaiting the announcement of the successor, Fujifilm is providing another announced firmware update for the X-T3. It's mainly intended to bring improvements in the area of autofocus -- the tracking of eye AF should work more precisely, and the recognition of and automatic focusing on faces in the picture should also be improved. Image content in the foreground is to be kept sharp by the autofocus without being disturbed by subjects in the background.
Whether these optimizations also work when filming with the X-T3 is not explicitly stated in the description. Especially in the video area, however, the occasionally occurring problem of focus pumping at minimum aperture should be solved.
For the upcoming X-T4, various possible, exciting but unconfirmed specifications and presentation dates have been circulating on the Internet for some time now; an announcement at the end of February is currently expected. It remains to be seen whether we will then actually get another 6K camera to choose from.