Hello Henry,
MDS 2012 SP1 creates any new databases with 100 (SQL Server 2008 and 2008 R2) compatibility mode and would not recommend changing the compatibility level (unless your DBA likes experimenting and the pains associated with it).
I am not sure as to why this the case, I can only speculate that a non 110, SQL Server 2012, database behavior is required for MDS 2012 to work.
Kind regards,
M