Oda will make Shanks look godly in terms of power in that fight, no way that doesn't happen with his poster boy. That being said it's important that, at the end of the day, Blackbeard's superiority will ultimately be highlighted in no uncertain terms.
Shanks being an utter monster who gets some glorious moments against Luffy's EOS opponent is totally fine but I swear, if Oda puts an asterisk in Shanks' defeat that could make one seriously consider "what if" scenarios where he could have defeated Teach...
It'd be terrible, lol. EOS Teach needs to be that guy.