You're crying
Wings mean you're close in strength and all to support your captain to become PK
Go cry to Oda
No flat earther
Wings is nothing more and nothing less than a callback to the volume 73 SBS, where Oda answers to a question saying that Zoro and Sanji don't get along but still are two trusted men who cover Luffy's back.
Nothing more nothing less.
The same term used in that issue was the one used for the Wings thing said by Robin and also wrote by the editors ad the end of one chapter.
There's nothing more than that.
I know that you wank yourself everyday to the idea of a yaoi between a green haired guy and a blonde guy being on par, but that's not what Oda thinks, sorry.
What Oda thinks is that Luffy has dynamics of with Zoro, Zoro has dynamics with Sanji, and dynamics between Luffy and Sanji don't exist.
Luffy and Zoro share so many aspects and parallels, while Zoro and Sanji, while sharing some ones, still have completely different backgrounds, goals, paths, powers, benchmarks.
That's why there are two dynamics in Monster Trio
Luffy - Zoro = The captain and his close right hand man, the Sun and his Moon, both Conquerors (only ones in the Strawhats), both Worst Generation Supernovas (only ones in the Strawhats), both with top tier as their benchmarks (only ones in the Strawhats), both with fighting oriented goals (only ones in the Strawhats), both with Advanced Haki (only ones in the Strawhats)
Zoro - Sanji = The strongest crewmembers, the ones who due to that strength cover the back of the captain far more than the other crewmembers could ever do and therefore can be called his wings; the ones who therefore can help the captain in the direst moments of his rise to become the PK