Sorry if I've missed it – is there a collective evaluation of the 2017 wishlist process somewhere? Was there a reason why one wasn't organized for 2018?
Topic on Talk:Developer Wishlist
In my personal opinion, being asked to express wishes often creates an expectation that someone will take care of fulfilling these wishes. That requires a process and assigning available resources. The latter is not the case so far, as far as I know. Also see discussion in https://phabricator.wikimedia.org/T149635
It did not seem worth the effort as fairly little progress happened on the 2017 tasks. See T158149 and T158148. It was an experiment that, at least in its current, voluntary form, did not work out. Or maybe it wasn't about the voluntary part but lack of being actively promoted through the year.
Also, I don't think priorities change so much during 1-2 years so if some group wants to fix developer pain points, IMO the 2017 list is still a fine starting point today.