Advice to young fans and young fandoms: You don’t have to let creator Q&A reveals of “canon” spoil your fun with fanfic and fan art. You’ll be a lot happier in the long run if you don’t give in to the idea that you have to retcon all your fan works and tear down blog posts about your headcanons every time a creator lets slip some “fact” online or at a convention.
Creator reveals aren’t canon unless they happen in the actual work. “Word of God” and “Canon” are separate categories.
(And I say this as someone whose actual religious tradition involves venerating both of those things and still considering them separate categories.)
It doesn’t count until it sees print/is given official screen time.
I would take it one step further and say even if it does happen in canon, it doesn’t have to ruin your fun. If you really care, mark your fic as canon AU. But there are few enough works that the canon itself stays consistent for its entire run; you don’t have to commit to the most recent version.
Don’t think of canon as the foundation you build on, that can be knocked out from under you. It’s the soil you’re planting in, and once your garden is growing, you can afford to throw away some of the rocks getting in the way of what you’re creating.