I always liked the facility and backzone map from beta 1 and maps like bunker_stinky, but i don't miss the old cradle.
So i cannot clearly say yes or no. Instead i'd like to list pros & cons:
+ nostalgic feelings of long time GES players
+ some maps like bunker are still missing a new version
+ the sewer in facility really helped the flow of the map
- due many changes in the assets, a lot of stuff would have to be included into the .bsp
- recompiling of the maps would be neccessary in order to avoid naming conflicts with the current versions
- it could cause confusion if there are two allmost identical maps
- someone would have to put a lot of freetime into converting these maps
- the original creator might be against the reappeareance of his old map, since the changes were made to improve the map.
- some maps are allmost ready to reappear in the next release.
Sadly a lot of cons and i'm sure i missed out a few things as well.
I'd absolutly vote for third party maps which were never remade for beta 3/4 (ge_bunker_stinky, ge_4towers, ge_stack_doc, pd_area52, nf_fortknox, and a few more i missed out), but no for all thouse maps that have a beta 4 version.