As a current MB Plat member, I'm more concerned about going the other way. The regular Platinum 25k offer says:
If you are identified as a current American Express® Cardmember, you may not be eligible for this welcome bonus offer. This offer is also not available to applicants who have had this product within the last 12 months or any Consumer ZYNC®, Green or Gold Card account within the last 90 days
I hope that carries over to any higher offers in the new year. I have to get my $200 for 2014 before I switch.