It was, and I did not much care for the movie. Gosling looks great in pink glitter. I actually preferred that to his red carpet outfit.
I think Stone was surprised too, although by the time of the ceremony she was a front runner along with Gladstone. Stone was deserving, but Gladstone was too, and Stone won for La La Land not too long ago. Also I suspect that this was Gladstone's only shot at the top prize while Stone will have many such opportunities in future. The Best Actress category was unusually competitive this year.