The suggestion is to keep at least some decency for the most important ladder and exclude heroic gear from 3s. There is a very good reason AT decided to restrict gear for so many years for a more fun, skilled and balanced metagame. Now the suggestion is not to ban heroic items completely and allow them as usual on 2s/bgs, but restrict the 3s ladder only to keep it competitive and more skill based.
Currently with the 284 metagame and more buggy icecrown core the gameplay is not exactly skill based and who really gets hurt from promoting more skill based meta?
While I do agree that 264 meta is more balanced, this is a very bad idea. 3v3 already is a dying bracket. What do you think will happen once you prevent most of the potentially active teams from queuing by placing a gear restriction on them? Not many people are willing to farm another set of gear just for 3s, not even on Blackrock. It makes even less sense for Icecrown and Lordaeron if we include crossrealm into the equation. Do you really expect people to spend months raiding for worse items than the ones they already have just so that they can queue?