Obviously a lot of people may find the rebalanced grounds not rewarding enough in terms of EXP/gold (or even a big waste there, which some can't or might not want to afford). And that is certainly understandable.
Hence, long-forgotten spawns will be quite crowded again. I noticed among my friends, that they started revisiting (as you mentioned yourself) Glooth Bandits, Deeper Banuta, Warzone areas.
Also, places like Gold Tokens monsters and bosses are quite popular these days. Obviously specters in terms of exp.
It goes without saying that since Falcons are one of the best spawns in terms of exp and profit, they are severely overcrowded.
P.s. after the first change that Cipsoft introduced (lowering the Feru seals), people on level 600 were doing 1.6kk exp/h on DT seal... It's more than obvious that they will move to mid-level range areas to hunt again.