If it won't be 30 days anyway (as the 50k plat offer is going away) is there a point in me waiting another week?
The issue is that it takes some period of time for AMEX to realize the card is closed. If you do it too soon you may get a letter saying you already have the card.
Then again I have had 2 of the same cards, so it's definitely a YMMV situation.
The period is very likely less than 30 days. 30 days is just what I tell people to be sure you don't get that letter.
Maybe it's 1 day, maybe it's 2 weeks. Maybe it works in sweeps and there is no right answer? Can't really tell ya'.
As long as you apply by the 03/30 though you shouldn't miss out on the offer, but you never know with AMEX. Or go for it today and let us know...