Instead of giving blasters mez prot, which the devs most likely won't do, how about a reduction in the amount of mezzing enemies in the high levels?
I can guess that they have a high number of mezzers in the higher levels in order to have a chance to hold scrappers and tankers. Well this hardly ever happens anyway that I've seen on my kat/regen or fire tanker, even with the reduced mag mez prot. So it makes the game miserable for blasters and doesn't achieve its intended (as far as I can guess) purpose. Nice.
I'd recommend trimming down the number of mezzers and making a few mezzers have a high mag mez. Mag 6 perhaps for some elite bosses or other selected mobs? For instance when a malta zeus hits you over the head, concept wise one could see where that could stun more heavily then say a beanbag.
This would result in a net less-time-spent-mezzed for blasters, and would mean that scrappers and tankers could feel occasionally slightly threatened by mez.
My guess is that even this is too much work for the devs as it appears they would like to think of CoH as being in the maintenance/bugfixing phase. But one can hope.