According to Dave Meltzer on a recent edition of The Wrestling Observer Newsletter, the original plan was for Dr. Maroon to re-evaluate Daniel Bryan on 3/27 before Smackdown in Pittsburgh. This would have given WWE almost two weeks to work on creative plans for WrestleMania, in the event that Bryan wasn’t cleared.
If Maroon didn’t clear Bryan, not only would that have meant that Bryan wasn’t performing at WrestleMania, but the creative team would then begin developing plans to write him out of the Smackdown GM role as the belief was that he would begin preparing for a run with another promotion in the fall.
However, it was likely Vince McMahon who insisted that Maroon evaluate Bryan this week so that they could settle on the WrestleMania plans and start building whatever angles they needed to do to set up the match and presumably to announce it on 3/27 on Smackdown. Vince McMahon moving up the date for Dr. Maroon to re-evaluate Daniel Bryan forced Bryan to fly in from Abu Dhabi to make the appointment. After the meeting concluded and Maroon cleared Bryan, he was said to have “tears in his eyes” and word began spreading backstage at RAW that he was likely returning.
When things were finalized and WWE made the announcement on Tuesday afternoon, it was because the company wanted to capitalize on the news and generate a big rating for SmackDown. It apparently had nothing to do with WWE wanting to be the first to break the news or at least get it out before it spread on the internet.
Source: Wrestling Observer Newsletter