This is only partially accurate. My Arborwyrm is back in my journal, but I do not have any of the Bestowed mounts from the mini-meta achievements that are a part of A World Awoken. Thus, the fix has still failed at least people that were granted them retroactively with the patch’s launch. (They don’t even show as uncollected in the journal either, which is typically a status only reserved for limited-time or otherwise no-longer-obtainable mounts.)
Missing on the close order of three mounts here; not sure which ones they are.
I just noticed because I gained the first two Plunderstorm mounts (plus the Trading Post mount), and my mount count was still the same from the end of February. (When I bragged about getting GMOD in my guild chat.)
The new DF meta mount, Taivan, has a very interesting bug. It shows up in the mount panel but when you “mount” it, no mount appears but you do get the 100% ground speed buff.