86.152.200.4 wrote: I'd say that he was joking.
Do you have a source for that? He spoke to The Fan Show as if she were alive. It might have been something of a joke in 2008 on set but RTD has now made it happen. This sort of situation can be likened to Steven Moffat jokingly stating that Nardole has invisible hair - something which made it onto screen in Twice Upon a Time! At the end of the day RTD's statements about the canonicity of the poem can be put down to him caring about his character and wanting to clarify that she had a happy story in the end. His interview for Radio Times also backs this up, he also echoes the story about Phil Collinson:
Absolutely. She's my character, that's my episode. I say that's true.
I look forward to an admin making a ruling on the anthology, hopefully sometime in the near future!