I'm not sure I agree with the take on Sisco in the catching situation.
I don't view Joseph as the starter and limiting Sisco's ABs. Joseph is 31 and should be part of the development process for Sisco. (I heard one interview
with the guy and was sold) If I'm the Orioles, why don't we value Joseph? Put 3+ years of guaranteed money on the table. He should serve as the compliment to Sisco over the next 3-4 years. Doesn't have to be a straight platoon, but Sisco should be getting 100+ games. Wynns should be serving as the backup depth at AAA.
In the immediate future, I think that comes down to whether or not the Orioles and/or Joseph are ready for him to be in that role. If the thought at the beginning of the year is that Joseph will get the bulk of the playing time, then what will be deemed more valuable to Sisco: exposure to the majors, or more at-bats and innings behind the plate in Norfolk? The Orioles have enough in place for Sisco to continue developing at the major league level, but his playing time--whether it is a straight platoon, or something similar--will have to be considered.