The distance you have to travel to get firsties does constantly increase, no denying that. When Tsu had the CG, I had to travel 500 LY away from it for the firsties and even at 1k I sometimes ran into stuff already claimed. When LA had the CG however, it was just 300 LY and I had firsties claimed. I don't think I travelled more than 500 LY from it and I had lots of firsties in Wregoe and Wredguia.Anyone who worries about running out of things to explore hasn't done an exploration trip more than 2000ly from Sol. I occasionally encounter a star that someone else has explored. But it's very rare -- less than 1 in 1000.
I think Nebulas and points of interest are goners now as well.
However, when planetary landings become a thing, that's another firsty opportunity for FD (I hope they don't pass on that)
first discovered by cmdr y
first landing by cmdr x