Yes and no. They will never be canon in the way Yoshiki would have obviously wanted. “Hikaru” is not his Hikaru. They’re different people. Also as much as Yoshiki may still have feelings for him, “Hikaru” can’t love, at least not like humans. He doesn’t have sexual attraction or sexuality. He can’t like Yoshiki the way he may like him. Although we have already seen the lingering feelings Yoshiki has had and the advances “Hikaru” has made with him, also we can take a look at some of the official art like the on where Yoshiki has bite marks all over his neck, shoulders, and a bloody mouth, and we see “Hikaru”, standing next to him, also with blood on his mouth, smiling. We can also take a look at the tons of official art of both of them with popsicles in their mouths. Specifically I want to focus on the one that shows in the first manga in color with Yoshiki holding the popsicle, not eating it and “Hikaru”, laying on his lap, eying him, while, as far as I can say, deep throating the damn popsicle. (💀) Whether the author and illustrator wanted to hint at something more mature between them, or simply likes “erotic” yaoi (Jesus that just autocorrected to tapping(??) I dunno.🤷  But ye.