False. Do your research before making such a claim.
How is it false? They would've gotten DG on the same day or within a week, only it would launch for everyone.
Because doing it with the different prices per platform would be considered "Price Gouging/Fixing" in the U.S., and that is a type of business fraud that's punished particularly harshly by the U.S. Government. Even Microsoft can't beat that wrap, so we get exclusivity deals.

False. 360 players have paid for tons of DLC that PC and (sometimes) PS3 players got for free in patches. See: Left 4 Dead.
MS also forces updates to add ads. You're delusional if you think Microsoft even slightly cares about their LIVE customers.
Price gouging would be if they said; "Here's Bethesda's $20 DLC, but since it's an exclusive, and the only way you can get it is through us (Xbox LIVE), we're going to charge you $40 and you're going to like it." That's Price Gouging.
So was Left 4 Dead's major 360 update illegal?
Microsoft: "Oh, here's some free DLC. That'll be $20, svckers. Keep payin' for peer to peer multiplayer too, lol."
Hmmm I'm gonna wait on that one personally. Launch model consoles don't seem to fare too well... *looks at launch PS2 and early model 360 which both broke*
But yeah, not much point splurging on a 360 now either

In all fairness my launch PS2 still works. My RL friend has been through 4 360s though, one of which he had to buy because MS refused the warranty twice even though it was E74.
They got me. I'll be buying a 720 when it's released next year. Not going to buy a 360 though.
If you're perfectly okay with supporting these kinds of practices, sure. The 360 is one of the single most toxic gaming products to ever see release thanks to how M$ has mis-used the added influence and abused their closed platform. What could possibly go wrong if the next one is successful too?
Well, I guess we'll get to see if they follow through with their plans for in-game advertising. Supposedly it's only for loading screens, but I'm willing to bet a month later some hacker / modder would figure out and prove that the loading times are artificially extended to make sure the full ad plays.
In any case, I don't think Bethesda is faultless. I think Microsoft bears most of the guilt (you know, as the instigator), but to say Beth is innocent is a stretch since they are complicit.