A little late okay! I just finished the Dawntrail MSQ today.
In June, I completed 20 achievements- 13 being from Endwalker. I got 2 minions (1 from DT), 1 mount, 11 songs (1 from DT), 3 bardings, and 4 triple triad cards- one being the elusive Eden's Promise that I've heard about!
With the release of Dawntrail, 132 achievements were added. At current post (3 days into July) I'm 64% instead of 66%. I think I might've been 63% on drop?
With finishing MSQ, I'm excited to see how many new Dawntrail achievements I can get before the first actual patch.