Gaban...he might not be as exaggeratedly strong as when the leaks came out but stop ignoring context.

Gaban faces base Luffy who is going easy.

Gaban smacks him with the key and shoves it into his mouth.

At this point Luffy should realize Gaban’s strength.

Gaban sends out a slash with 2 axes that destroys the tower/blows Luffy away/forces Zoro to use 3 swords to block.

Gaban sees G5 and makes a mental note that this is what he wanted to see.

He “gives up”.

•

This was an obvious test to make sure what Shanks talked about was true.

Gaban is not in a situation like Garp where he is trying to save the new generation.

This is the earliest bare minimum showing of his strength in an exhibition type match, which was already able to push Luffy and Zoro to their strongest forms.

With the way Gaban talked at the end of the fight, he will probably either fight Luffy again at the end of Elbaf as a test or he we will go all out in some capacity.

TLDR;Nothing in the most recent chapter upscales Luffy or Zoro, Gaban gave up because he achieved what he wanted.