Looks like there are 0 fixes to bugged achievements in patch 2.3, alas.
The main changes will be to increase the number of reputation organizations (why they decided to split one of them across factions is beyond me) by three, with presumably a larger number of achievements in the events tab (Bounty Hunter Contract week), flashpoints (the two Titans of Industry flashpoints), planetary (CZ-198 planet), and perhaps companions (Treek). None of these are confirmed beyond the 3 new rep factions, to my knowledge. I guess we'll see how much they care about achievements if they bothered to add new ones or not.
New Galactic Reputation Organizations! Three new Organizations have been added: The Adjudicators (Republic), Ordnance Acquisition Corps (Empire) and Bounty Brokers Association. Details under Legacy
New Event: Bounty Contract Week! Each month, players can undertake contracts and pursue dangerous criminals throughout the galaxy! Adventures begin on Republic and Imperial Fleets with a mission given by mysterious Bounty Hunters who are toting a "friend" encased in Carbonite. The first Bounty Contract Week begins on August 14th and will continue for seven days.
I'll drop the dates off of those who currently have 6 rep factions at legend in six weeks, when folks can attain legend status for some of the new reputation factions. Depending on what changes, I'll roughly re-calculate percentages of each achievement tab to account for the new achievements and figure out what the new max number of points is.
Finally, as usual, Dulfy already has guides
for new patch 2.3 things.