without even having played it yet. Achievements for reaching levels 10, 30 and 50. I wonder if this will also impact the vendors merchandise - there are some parts in his inventory that read something like "for having retrieved...."

Same for me. I just started the rogue-like version (just the DLC) from the Main menu and got all three achievements simultaneously

Same here - wasn't right away though. It was after 2.02 or 2.03 (IIRC) was installed.