I just did a very short tour, checking for HGEs. This is how it turned out for me:
Started at LHS2494. System states: investment -> launch, start FSS -> less than 4 minutes in game: one HGE during my scan. 26 minutes remaining.
Content of the HGE 3x core dynamics composites, 2x proprietary composites
Jumped to LHS2541, states: none -> use FSS -> two HGEs. One of them only has 2 minutes left, so no way to get that one. The other has like 15 minutes left, so i visit it. Content of the HGE: 2x core dynamics composites, 3x proprietary composites
Continued to Veneri. State: war -> started the FSS, pirate interdicted me while scanning. So can't tell the complete status at arrival. After destroying the pirate:
1x HGE. state: CIVIL WAR. 38 minutes remaining. Interesting that it's civil war. There is also civil war in the system, but i did not see that state on the galaxy map. Content of the HGE: 5x military grade alloys
So within very limited time, i was able to find 3 HGEs which i was able to reach and enter. This is very different from what was reported here. Possible theories on this:
1. I was extremely lucky.
2. Those who reported the early problems were very unlucky.
3. There were some issues right after server restart, which needed a few hours to sort out.
4. Some of the first reports were heavily biased towards the drama side.
5. I did this late at night, when fewer people play.
Due to how the system now works, that USSes are created by a central instance, but any player entering a USS can "use it up", i would guess that it's actually #5. When there's plenty of players around, the first one to spot the FSS goes for it and uses it up. The next one spawns a while later, but again the first pilot to notice it can quickly get it, the rest have a very slim time window to even just see it. Thus the impression is formed, that they don't exist at all.
It'll be interesting to get more feedback from more active times. If now over daytime also HGEs are being found, it most likely was #3. If they again are not found, then #5 is very likely the reason and FD would be well advised to look into spawn rates and maybe increase them when many players are active.