Yes, experienced the same behavior this week. Purchased a ticket on 4/16. In the past, 50% rebate has posted within 24 hours. As in your case, rebate has still not posted. Called and received the same canned response about April 11 protocol change and the 10 weeks timeframe. I have both the Personal Platinum and the Biz Plat cards, but paid with the Biz Platinum Card.
Thanks for confirming, foo and others.
Several more tickets purchased, all with no rebate posted yet.