Thank goodness they are not as hung up on having a button as it initially appears:
"We are currently considering adding single-click functionality for the most-frequently used languages."
Sadly, while that means that the overall experience will be improved, it will solve exactly nothing for those who are unlucky enough to use a less-frequently-used language.
It has already taken multiple clicks for users wanting to read English Wikipedia in a language that wasn't one of the nine in the sidebar. In fact, clicking the "287 more" link at the bottom of the left sidebar in the old design brought up the exact same box that clicking the "297 languages" link at the top of the new design does, with the same list of languages in the same order.
Alternatively, one could create an account and set a default language, or visit a wikipedia site dedicated to that language.
I've always seen all the language links in the sidebar without clicking anything. I can see how, if you have had a different experience, the new arrangement might seem less of a disruption.
I think they might mean most-frequently used of that user (I think the "suggested languages" already are supposed to work like that.) But that presumably requires an account.
"We are currently considering adding single-click functionality for the most-frequently used languages."
Sadly, while that means that the overall experience will be improved, it will solve exactly nothing for those who are unlucky enough to use a less-frequently-used language.