Regarding javi/yuzu relationship, I'd like to think they're friendly rivals rather than soulmates/bffs/bros. At least from what I read from the interviews of Brian/Tracy/related indv, they don't really hang out together and they are not training at the same time. And we know they have very different cultural background and hobbies etc.
To me, it isn't surprising at all that Javi doesn't know/care to know Yuzu very well. Despite what shippers may see, I think it is already very admirable just to be polite and respectful to another top skater fighting for the same resources.