It can’t be disputed that George borrowed some EU concepts in The Clone Wars show and in his sequel trilogy ideas (i.e. Darth Talon), so he definitely considered it a form of source material to draw from. And its well known that he would veto ideas from EU authors if he disliked those ideas (i.e. having a clone of Vader in Dark Empire instead of Palpatine). Yes, we get that George didn’t consider it part of his own canon, but he still oversaw the EU, in large part.

And if it was never counted as Canon, then why did Disney bother to announce they were decanonizing it? The Canon “tier” system existed for a reason. EU was a lower level of Canon, and existed in a sort of grey area, but it wasn’t entirely non-canon like it is now. The binary “Canon/non-canon” distinction didn’t apply back then.