They aren't going to do this right now, but they almost certainly will in the medium term. It would be legitimately shocking if they didn't continue to follow the same path as Google, Facebook, and pretty much every other big tech comp. In OpenAI's case they have even more incentive to abuse their users since they collect so much detailed personable data and have ways to make ads unblockable by including them in outputs and skewing model weights. I've seen absolutely nothing from the company, it's CEO, or investors that make me think they won't do the normal thing of gradually making the product worse in order to wring more value out of their users.