Eh. Writers wondered whether Donna should date any of the boys, but I don’t believe Wolfman ever explicitly said he planned to pair them up. I would need to see a credible source reporting otherwise. Wolfman and Pérez brought Terry Long into the mix pretty quickly to be Donna’s love interest because they decided she shouldn’t be romantically linked to any of the Titans they were actively using.
Now, the previous creative team (doing the tail end of the first Teen Titans title) did have a confirmed plan to have the title continue after the introduction of Titans West, and Dick was going to be in a love triangle with Bat-Girl (Betty Kane) and Harlequin (Duela Dent). Of course, that run didn’t get to happen as they hoped. But, if it had, we may not had gotten New Teen Titans, which is what popularized the team and gave us so many iconic original characters.