Honestly? Plausible.
Take a look back at Chapter 546, where Mr 3 gives Luffy boxing gloves with his wax. And Luffy is in tears because he thinks he looks so cool.
And then even further back in Chapter 314. Where Luffy gets his afro...and boxing gloves. And we can now see that the afro was kinda-sorta foreshadowing Gear 5. It's not impossible for the gloves themselves to be part of something.
Could this be foreshadowing? Luffy seems to have a affinity for boxing gloves for some reason. It's possible that it was all Oda foreshadowing Joyboy's eventual reveal. I honestly wouldn't even put it past him. Luffy might be subconsciously "remembering" really loving boxing gloves for some reason, from his "past life".
Now, this could be reading WAAAAAY too much into it. And I have no idea why the gloves would be important. But...I'm still going to say it's plausible that Joyboy has gloves as part of his design.
