With the disclaimer that I am not a developer or package maintainer — I am but a lowly, lowly cook moderator — the package that replaces wxgtk2 supports all that wxgtk2 supported.
So it’s only the replacement of one package by a package with another name, and while it may be necessary to remove wxgtk2 first, it is perfectly possible to do this without removing all that depends on wxgtk2. But for that you have to read the man page for pacman.
