It's what it meant to him. And I very highly doubt he meant that Kirk instantaneously entered into eternal bliss from that moment forward, but if you want to conflate it to that and rush to a rash judgment of him in the process, I can't stop you.
Saying that Fuentes never said it, is a lot different than saying he didn’t mean it as he said, so actually your title here is inaccurate, not mine.
Fuentes did in fact say Kirk was in heaven because that is explicitly what “receiving the beatific vision” means. I’m not discounting that Fuentes might be so ignorant about his faith that he just doesn’t know what the beatific vision even is. That could be, or it could be that he is just the average Novus Ordo heretic who would say the exact same thing. Heck, I know at least ten people at my old SSPX Church who have said Kirk is in Heaven.
If you want to defend him by saying “he didn’t mean it the way he exactly said it!” then go ahead. I don’t really care. Regardless, the statement is still materially heretical at the very least.