Well, first of all, I am glad the RECF did not enforce anything on the spot. That would have been a shame.
As I see it, Karthik recently ruled that the screws can be replaced with screws that are not identical. If that is allowed (and it is) then I really do not see a difference with this. Zip ties do not loosen and the idea of being able to quickly swap out a motor is nice considering the quality and expense of the motors. These motors often fail at very inconvenient times and being able to quickly replace them is a benefit to everyone.
I see no logical reason for this to not be allowed so long as you are using Vex legal zip ties.