A coincidence isn't an irony. You're not paying for the game to get some sort of reward or a better experience, you're paying to support GSC and because it's the right thing to do.The Irony is, this state of affairs was reached just after the game was pirated, therefore allowing the pirate copies to be at least more playable than the Pre-ordered ones sent out the day it was released here(yes I too pre ordered it, several months ago!). You must be an American if you cant see that as slightly ironic.
It's no more ironic than when the pirates got Doom 3 days before the people who paid for it. If you bought Doom 3 and the copy protection didn't work with your dvd drive thus stopping you from playing, that might just be an irony.