There is no community consensus about activating this feature. The discussion in pl.wiki (link in the description) shows that over 50% of users are against this option, so I really do not understand how it is possible to deploy it on pl.wiki...
I also understand an 7 for and 5 against, and, on may wikis a vote with simple majority like that one is enough to deploy a feature.
I'm claiming the task while I'm checking with the community.
Where did that check happen? I can't find any recent comment in https://pl.wikipedia.org/wiki/Wikipedia:Kawiarenka/Og%C3%B3lne#Flow_na_nast.C4.99pnych_stronach ?
The result of the discussion on pl.wiki is inconclusive. The diffrences in counting for and against votes by different users are caused by the fact that using "for" and "against" icons is not required in pl.wiki discussions and some votes are not fully clear. The fact is only that, there is no consensus on this issue, which is required to implement such change.
As an opponent of this change, I can only add that implementing this feature, which gives every user the possibility to change the mechanism of user talk page is potentially harmful. User talk pages are not their private property, but are only a way that others can use to communicate with them. Implementing two mechanisms (in wikicode we discuss on two pages, in Flow the whole discussion is on one page etc.) can be problematic for some users, and in my opinion Flow testing should not be performed on user talk pages in the first place and should not be available in this way to every user. In other words: Flow could be implemented on user talk pages if and only if the entire community agreed to switch the mechanism of all user talk pages to Flow.
If there's no community consensus, the task is declined. Plus the bug is going to make in April one year, as well as the plwiki discussion. We require fresh discussions to implement things. Maintenance closure of old tasks.