There appears to be a typo in how VASP writes the METAGGA flag to OUTCAR. Regardless of how the METAGGA tag is set, the line
is always written to OUTCAR. Looking through main.F and reader.F, this seems to be a bug from when PKZB was the only meta-GGA included in VASP, and in a non-self consistent fashion. In main.F, the reader subroutine searches for the METAGGA flag in INCAR, but expects the result to be logical. Because the correct type should be character, this returns .False. erroneously (see lines 1375 and 1448 of main.F in version 6.2, where a logical variable for the METAGGA tag is read in and then written to OUTCAR, respectively).METAGGA= F non-selfconsistent MetaGGA calc.
When PROCESS_INCAR is called again, as in metagga.F, the type is correctly set to character and the right meta-GGA is selected from INCAR. So this isn't a serious bug, but I and my coworkers have noticed it and want to be assured that it's just a typo.