We have been on version 5.x for some years now and changes are afoot; items that spring to my mind include:
1. Support for JTA 2.0, EE 10 and jakarta namespace (this work is already well under way);
2. Java SE 17 and (possibly) dropping support for SE 8 (i.e. SE 11 will the minimum supported version);
3. Improved support for asynchronous APIs (although we continue to be tied to XA and very few resource managers support the asynchronous component of the XA spec , there are still things we would like to do in this area);
4. Drop Transactional Driver  in favour of Agroal ;
5. An improved cloud strategy around recovery (again we have already started work in this area).
section 3.5 Synchronous, Non-blocking and Asynchronous Modes