>>528032151
>Couldn't that be because Shirou still has the avalon sheath inside him on that route
No, it couldn't. For starters Avalon's powers are dependent on its user's connection to Artoria, not the other way around and once that connection is lost it loses power and become inert relatively quickly. Also, Nasu has made it a point that it isn't just a matter of having the blueprints for Excalibur, Shirou does have them, but (supposedly) they're not enough, that's why all the talk about images, hollow weapons, sacrificial fairies and whatever other bullshit he randomly comes up with on the spot.
The elephant in the room is that those retcons regarding Shirou's powers ARE contradictory AND pointless and Nasu just added them because he knew that after F/SN he would no longer be the sole writer who could use Shirou Emiya and, like a spoiled child that breaks their toys when their toys when their parent forces them to share them with their siblings, he added to them to handicap Shirou/Archer because he didn't want anyone else to be able to easily write stories about his OC (not that it matters, because said writers just keep giving him the middle finger, best example being the Waver stories).