As I am one of the few 76's and most likely top 3 by experience on the server my opinion on the class change / groups is as follows:
I think its a healthy thing to keep server alive and flowing but it needs to be updated according to class balance ( patches ).
If i was in control what I would do is:
As soon as open beta is announced, disable all class changes from this moment until 3 months into 2.0 patch have passed. After 3 months have passed rebalance the groups according to class strength in farming.
My current groups for patch 1.5 would look like this:
1) Overlord,Prophet, Warcryer
2) Bishop, EE, SE .
3) Temple knight, Shilen Knight, Paladin, Bounty Hunter ( only to reroll from ), Warsmith ( only to rerroll from )
4) BD / SWS / Phantom Summoner
5) Treasure Hunter, Plains Walker, Abyss Walker,
6) Hawk Eye, Silver Ranger, Dark avanger
7) Elemental Summoner, Warlock
8) Gladiator, Destroyer, Warlord, Tyrant
9) Necromancer, Spellsinger, Spell Howler, Sorcerror, Phantom Ranger
edit: Debateable to me is if DA should be lower, but i based it on farm speed and not desirability in groups. If you factor in desirability in groups. Daggers could swap with bd/sws and go from 5->4 and bd sws down to 5 from 4.