When ROH had worked out a date to run a show at Madison Square Garden the day before WrestleMania, WWE called MSG and attempted to block the booking. MSG responded by pulling the date from ROH but then Sinclair Broadcasting, which pretty much owns ROH, threatened a lawsuit. Not wanting to “take a lawsuit bullet” for WWE, MSG went back to ROH and re-offered them the date, which ROH obviously accepted.
One of the dynamics at play was the relationship between Sinclair and WWE, or more accurately the pending relationship. As a major television broadcasting company, Sinclair owns and operates numerous FOX affiliate stations and ultimately would have a lot of leverage over WWE.
They could basically threaten to not air SmackDown in their owned and operated stations which is plentiful enough that it would seriously affect SmackDown’s viewership numbers and ratings. On the flip side, not running SmackDown on Friday nights would also end up hurting Sinclair as no other local programming could get anywhere near the numbers that SmackDown pulls. So at the end of the day, this is a win-win situation for both Sinclair and The WWE that they both agreed and came into terms and that The WWE didn’t pursue blocking ROH’s MSG Show.

Source: Wrestling Observer Newsletter