I'm more inclined to believe that the actual Golbez is our shard if anything. He seemed more heroic (to a fault perhaps) than Durante or Zero, praying for those who don't even deserve it, still holding onto hope despite everything. Sounds like something WoL would do. The way our echo vision of Golbez is depicted is us seeing the flashback happen from his perspective as if we were him, though granted this also happened with 8UC timeline G'raha dream in Shadowbringers. The memoriate that held these memories also dropped into the Zodiark-voidjuice-pit, so it's obviously going to come back as a plot device in 6.5.

Zero does have the edge in terms of our initial meeting feeling very suspicious and planned (with Hydaelyn's crystal reviving her and all) and Y'shtola saying that perhaps we were meant to meet, but I think after 6.2, she has become her own person and it doesn't feel like the game is actively trying to make any sort of comparisons between her and WoL.