Since the old versions of the official maps have the same names as the new versions, it's not possible to simply throw them into beta 4.
Beside that there have been changes to the weaponspawn system and other stuff.
If bringing back old maps was an option, i'd rather go for pre-beta 3 maps, edit them in hammer and recompile them under a different name e.g. ge_facility_backzone_beta1.
Just changing the name will fuck up things like lightning, soundscapes, cubemaps etc.
