It was a while back. You don't if you choose not to believe me, i can understand(I'm not going to search through the interviews and interviews just to find it), but I recall Nomura saying love, in the traditional sense(as in romantic, "Eyes on Me"-styled love), was not going to be an important theme in Versus. Other "types" were, though, including the love between family members and the love shared between comrades/close friends. I think I even recall Nomura saying Stella was NOT Noctis's love interest, though again, I don't recall where and when it was. The longer this fuckin' development cycle has stretched out, the more hard and annoying it is to search for articles to cite. How I wish this game would've just had a somewhat "normal" dev cycle.
But to throw in some theories(my own, of course), it makes sense, even with Tabata's "changes". For one, Versus(and XV up until recent, though we still don't know) has been influenced by the "mafia" culture. Mafia, who tend to act as "families" of power, not unlike royalty. Families would suggest familial love(love between those related to each other), and Noctis and his friends would suggest not only friendship, but a type of brotherly love.
Now Stella? If there are two things that could bind both she and Luna, it's their childhood relations to Noctis. In the earlier trailer(back when Nomura confirmed Stella to still be in XV), we see the girl running with Noctis(as a child). Stella was likely to still be Noctis's childhood friend, which would've made their "reunion" the gallery party the first time they've seen each other since childhood(if we are lead to believe that, of course). That still draws upon a close love through friendship, as childhood friends tend to be the most cherished of friends. Noctis and Stella are still friends, but the friendship Noctis has with her is different from that he has with his bros, yet doesn't resort to the tired, "I'm a guy, you're a girl, let's get together!" just for the sake of romance. I think Nomura wanted something more special and intimate, shared between two friends that went WAY back(before Noctis even became good friends with his broskis) and the drama that comes with the fact that he(Noctis) has to be pitted against his childhood friend(Stella), through twist of fate. It's no reason Nomura wanted to invoke the tears with HIS story. And we know Luna is similar(childhood friend), but it looks like, unlike Stella, she might have a closer relationship with Noctis(romantic, and more frequently engaging, as it seems like they are more familiar with their "adult" counterparts and kept in touch, unlike Stella). That's just a MY theory and nothing more.
