I think that Tesla wants to get FSDb onto HW4 cars, but most of them are beyond the development branch. So, Tesla integrated the latest widely deployed version into the production branch, being 11.4.4.
11.4.6 is obviously dead. And 11.4.7 apparently has issues delaying it from being rolled out. So, that leaves 11.4.4 as the latest acceptable version to go to HW4 vehicles.
All of which really bites for those FSD owners on the development branch waiting for any updates. With 11.4.7 possibly heading down the 11.4.6 path, I'd say that Tesla appears to be having difficulty getting past some roadblocks, leaving us in software limbo. We're almost six months behind the production branch at this point. Perhaps its time for some catch up?