does anyone know if amy and rory’s adoptive son, anthony, is officially canon or not?
Doctor Who doesn’t really have a canon as such as I understand it and a deleted scene is pretty tricky territory to begin with. I’d assume “officially canon” doesn’t really apply against this background.
(Steven Moffat’s descriptions of what wasn’t depicted on the show have often been accompanied by nods to the fact that this is really just what he thinks happened. If you think Amy and Rory adopted a child and called him Anthony, that’s more than good enough. If you don’t, they probably didn’t.)
Moffat also once said that it is all canon, all of it. The books, the audios, the Shalka Doctor, Curse of the Fatal Death, everything. I imagine that includes Anthony too.
That is the obvious alternative to “no canon exists”, I guess. All stories are true.