Perhaps they want to kill off SAP's Sybase division once and for all.
I believe that Micros was one of the last big support contracts that Sybase still had. Now that Oracle owns them, you can be pretty guarantee that new version of Micros ReS will have an Oracle backend.
But, hey, Sybase is a Dead Division Walking already. When was the last time you heard about them getting a NEW Fortune 500 contract?