If you guys want to know why it was changed in cataclysm, let me tell you a story. Back in the wrath-cata era of raiding, you needed to kill the final boss of an instance on normal mode before you could even step foot in heroic mode. Naturally, this meant that no one could even attempt heroic mode bosses until week 2. That is, until a Chinese guild called Stars (I think) had the clever idea of server xfering after their normal mode clear to get a world first heroic kill in the Firelands on week one.
A clever use of game mechanics for sure, but definitely not an intended one. Ever since the Firelands raid, blizzard has put a hard lock on heroic (and now mythic) raids unlocking the week after release, as well as retaining instance lockouts across xfers.
Say you find out your friends are playing somewhere else, but it’s hard to justify spending money. This just adds value to the realm transfers. Makes the transition more enjoyable too since you do get a double chance to raid in a week.
I guess it’s a good thing we can’t faction change on classic
Blizzard doesn’t have to explicitly state that something is exploitative in nature in order to decide that they want it not to be a thing. They’ve fixed dozens of exploits on retail that you or I might not even know about, that they make no reference to in any patch note.
