Things related to Microsoft:
Afaik many people related to the HoloLens left Microsoft and the only mention you still hear is their contract related to the military. Support is cut back to a minimum with sometimes inconsistent deprecation notices.
Things related to Unreal Engine:
I don’t think they will bring it back considering that they would develop for a (mostly) dead platform with costly labour.
On the bright side i’ve made a fork which brings back HoloLens2 to Unreal Engine 5.4.3 and fixes some issues related to shipping in rocket builds. Haven’t fully tested it at runtime yet but there is an issue related to sound streaming in debug builds.