Stuff like spikes spells and additional effects activating are not the same. If anything is close to remotely proving Saevel wrong, it would be that you can swap gear while casting, but I'm not sure that is really all that damning to his statements.

Moving from that, I think that more abilities like Occult Acumen would be more likely then melee while casting. I suppose the question is, why don't Red Mages have it, and why isn't there a variant for Ninjitsu, Blue Magic, Divine Magic?