yeh but like dude was leaving all his passion for his captain.. and Zoro is always talking so sincerely mostly, so Zoro calling Luffy his Oldest friend is actually a good development and feels much better and IMO to readers as well cause we hardly have anything for kuina but Zoro and Luffy dynamic is one of the best in the story
I disagree. Having nothing beyond Luffy makes Zoro a more shallow character. The reason something like "Nothing Happened" and bowing before Mihawk all for Luffy's sake were such powerful moments is because Zoro had hopes and values all of his own, but was willing to compromise them for Luffy.
The Wado Ichimonji itself is the symbol of the promise Zoro made to Kuina post her death to become the strongest swordsman for both their sake. Zoro did not forget that, as we just learned last chapter of him remembering that oath while crawling towards the blade. It is to him what the Straw Hat is to Luffy.