Yes, and now they (will) have ads in the lower tiers and eventually will add them in higher tiers as well. It's no different to Netflix's methods. Therefore the statement would have been proven right if it were claimed back then.
You can't just say because they've added more things the old things are over - the old things actually have to go away first. Eventually they may get there (or not). It may be another few years (or not). Nothing is actually now over though any more than it was now over in 2024.
Additional tiers to get people to move up as they enshittify the lower tiers. We already see it in other companies as well as OpenAI themselves so my inference is based on that, not to wait and see until they do indeed enshittify it.
That the inference would say these existing paid tiers should have already enshittified with the 2024 $200 Pro announcement is precisely why one does need to wait & see.