Just my two cents, but I do think it will be the end of the fare types.

I can't possibly see how they could keep 150% on PRO fares, that cost as much as a business ticket and at the same time offer 150% on a premium econ ticket that will sometimes sell for half that price.

This makes me think there is no room for all the types once PE enters. Leaving room for maybe 3 types in econ, 2 types in PE, and 2 types in J.
It think there will be a name alignment, adopting "Flexible" as the moniker for rather inflexible tickets and "Full flex" for tickets that actually has flexibility.