[[André]]a works, [[André]]é does not, [[André]]tá works until the accented character, where "works" means that the whole tail is linked (blue).
It's the same with many accented characters (öâñçś...), but then čćđšž seem to work in wikilink tails.
This probably isn't that new, but is more visible with the new, lighter link colors.
PS
What about [[Batman]]'s and [[a]]''b''?
According to en:Help:Link, they once worked.