I can understand why they have decided to postpone, and theoretically March is a better time to release - but I also think it will be hard to maintain hype and momentum for another couple of months. They're really going to have to think about their strategy if they want to keep the show in peoples' minds.
She's got a lot of critique already on the trailer but at least people were talking about it - it would have drawn curiosity views at least. A lot of things can happen between now and March and trying to keep that same level of interest will be tough - I can't particularly imagine Netflix putting a lot of effort in to keep it front of mind.
That said, it would probably have been worse reputation wise for the launch to go ahead on the 15th - a bit damned if you do, damned if you don't. As I said, I think Netflix have done this more for their own reputation than because they care about the success of the show or the public's perception of Meghan.