THIS CANNOT BE REAL.
Now, ESPN does this obviously because Disney owns both Marvel and ESPN*, and so someone at Disney stood up and was like, “You two! Have cross-promotional buttsex.” And they did.
Though I’m not qualified to hold forth on sports, I think you’re right that a plural verb with a singular team name will look odd, or at least British, to American readers. “Heat outlasts Thunder” is going to look more natural. Since a case can be made for either usage, and style rules are inherently arbitrary anyhow, I think you should pick the choice with which you are most comfortable and follow it consistently.