I mean look at other things. You can still program in C 89 or FORTRAN 77 or COBOL 74 (and no doubt there is somebody still supporting compilers and runtimes for those), but they are all obsolete standards.
Addendum: I think for standards like programming language semantics (which in case of Python is directly embodied in the C implementation), "obsolete" means there is a new standard by some official body (say, the developer of the old standard) that addresses shortcomings of the old standard. So "out of date" is the fitting equivalent of "obsolete" from the Oxford definition.