No. (It would be nice if bets were off, but the big man won’t make his bread that way. And if all bets were lost, the big man would lose his customers. So they just use the numbers at the end of OT to pay off.)
The biggest pain in the world is when you bet a 10-point dog, and spend the last two minutes praying for the game just to bloody end so you cover, but it goes into OT where the favorites win by 12. Similarly, hitting your under in regulation, but losing it in OT sucks very, very hard.
On the other hand, you might’ve bet the favorite, so in the last minute, the only hope you have is that the game goes to OT, so you find yourself yelling for a tie.
Sports wagering completely screws the way we look at a ballgame.