Its not as bad as I suspected. I just took a quick look at the routes I frequent. The fare was the same as before, with slight increases, depending on what you are looking at.
Basically the 'flex" branding was expanded to lower booking classes, so not full Y or full W or J only respectively. That is what I initially feared. It would be suicide for SU to do that.
Technically it was not possible to buy these new fares until today, November 1, 2016, the jury is still out if the old rules apply for tickets purchased prior to the switch.
I am taking an SU flight in about two weeks, departing outside MOW so I suppose i will find out.