I am not wrong. The runtime of the Adacore Community edition is under GPL, as are many libraries included in the Adacore edition that are not included in the FSF edition. Your binaries will be under the GPL. (Technically speaking, you could compile executables with this version of GNAT that are not under GPL by writing your own runtime. Practically, this is pretty much impossible and nobody has ever done it.)
The FSF edition allows you to compile executables without license encumbering, because it is licensed under the mGPL.