What is canon?

Well the Last Dragonborn is a officially a male Nord. But as for what they do? They kill Alduin, Harkon, and Miraak. Everything else is pure speculation including their political actions. Even killing Paarthurnax or sparing him isn't set in stone.

What YOU the player do isn't officially canon. Kill the Dark Brotherhood or kill the Emperor? Dang mixed choices, too bad neither are canon until the next game. Stormcloaks, Imperials, or neutral Civil War ending? All non-canon until the next game. CC content sure isn't canon either.

Was everything you did as the Neravarine or Hero of Kvatch canon? Nope. So why on Nirn would anything you do as The Last Dragonborn be canon? You think they'll sing tales of how he became a bard and recovered King Olaf's Verse? You think he'll be remembered as thane of every Hold? You really think he's the Archmage, Listener, Nightingale, and Harbinger? How could one being logically run 4 major factions? You think he really collected all Daedric Artifacts in Skyrim too? He certainly didn't marry Lydia either.