"Vcs-Browse" is a typo ("Vcs-Browser" is correct)

Romain, "Vcs-Browse" is a typo (having "Vcs-Browser" as its correct version), at least according to the documentation I wrote a long time ago (unfortunately not yet integrated in the devref ...).

So dpkg is right in supporting "Vcs-Browser" and the 52 packages you've found need to be fixed. Being a maintainer of one such packages (I don't know if I actually am), I wouldn't mind a mass-bug filing (priority wishlist of course) about that.