There's alot of non-multiboxers who have alt/trial accounts specifically for talking to the other faction, mostly for pvp-related reasons(e.g; lv1 Warr whispers: OMFG U NOOB IT TOOK 3 OF U TO KILL ME U SUK LOLZ EVEN THO I WERE IN TOWN AND U HAD 8 GUARDS + 2 PATROLLING WOLF RIDERS ON U HAHAHA QQ MORE)

Using and/or abusing the Gobbledygook system that muddles and befuddles what we type is more or less in the same grey area boat as AHK; it can be used improperly(Like a few horde I know that found & spam racial slurs to alliance nonstop through it), but it also has legit/less offensive uses(such as "Ag Ee oo D a p LOL" translates to "[Common] Me Lo ve Y o u BUR" and the less nice but still non-offensive one I personally came up with, "Ag Lol d D a p" = "Me Bur y Y o u" ;p); due to how limited it is and the majority of people only knowing a phrase or two at most it shouldn't be an issue. Plus, it makes sense: In any war, the opposing faction will have translators or even learn very loose, poorly-grammared(irony) phrases to communicate or taunt with.

The fact that all races of both factions could talk to each other without any issues whatsoever in War3 doesn't exactly support Blizz's decision either lol; plus, if Trolls/Undead/Tauren can learn and speak Orcish as their "Common" language, it shows learning is possible ;p