I would add to Journeyman’s list the withdrawal of the Tuesday Group Book Study
Wow. Of course, how could I forget that one? That was a big blow to the bros and sisters.
For years, the society had said that the book study group was the main contact point for every witness in the congregation - they even speculated that when the "great tribulation" came, it would be through the book study that everyone would be kept in touch with one another and sustained.
Then the GB2.0 just swept it away (along with all their other changes), claiming some nonsense about saving brothers the travelling time and 'freeing' an evening for personal and family study, when everyone knew it was really 1) to avoid liability in case of anything bad happening in a private home, and perhaps even more 2) because they were paranoid that small groups were not teaching the party line 'correctly'.
It's true that the quality of teaching in the groups was very variable, depending on how capable the elder or servant taking them was and whether the group had any dominant or overbearing personalities in it, but as BluesBrother said, the groups were invaluable in JW life (where there are few enough opportunities to socialise) for giving all the chance to chat and have a drink and snack together afterwards.
The org still pays lip service to it in that every witness is still supposed to be part of a 'group' with a 'group overseer', but the arrangement is a shell of its former self and has little meaning beyond the Saturday morning field service group, while the 'book study' has become just another dumbed down video-playback show as part of the midweek meeting at the Hall. Officially, it's called the "congregation bible study" but practically noone calls it that because there's very little study of the bible involved (even less now than in the days when they had verse-by-verse considerations of bible books) - it's more a "reading of a book/brochure written by the WTBTS".