I don't disagree about lack of space in the bubble being an issue. However, there should have been the ability to subtract as well as add ( simplistic lol)There was space at the start of 2023 - and still is now.
Had things not broken then, the space would have run out approximately now, though: PMFs were taking 2000-3000 systems a year pretty consistently since the start of the game. There were only 2000 left at the start of 2023. Even allowing for it getting more difficult for existing PMFs to expand into one of the few remaining systems towards the end, it would still have been now or not much later.
The breakage may have been caused by the live/legacy split - it was quite a while after that that they next added a new NPC faction to the game - but not having any urgency to fix it for PMFs was probably because it would only have been putting off the inevitable anyway.
The system did break and that's the point.
The original technology limited changes outside of server downtimes. Odyssey framework has more ability for dynamic changes. They tested that with spray paint. That made me laugh as Anarchy Online did the same in 2009 with the change in their database, except Funcom went the extra mile allowing players to spray paint. CLANS FTW lol.
So not disagreeing per se. I think the new npc faction was in all likelihood using the Odyssey Framework. Maybe the Thargoid invasions are clearing down the unused PMF's ?