So I did the gear update on almost all my eligible alts, and it completely scambled their actions bars. Is there any way to recover their old layouts? I really don’t want to spend the next three months figuring out through trial and error what buttons go where as my muscle memory gets things wrong… x_x
'Fraid not. 
You will just have to remember.
It happened to me once. It’s a bummer, but really not all THAT bad to remember and re-slot.
It should really warn you that it will reset everything not just gear, pretty sure it does but who reads that anyway.
Unfortunately there is no undo option and you’ll have to figure them out. Personally the gear update you get compared to the other headaches it brings is not worth it. .