That's really odd, yesterday i just recognized that my bunker map also has some missing textures and model errors in it. Seems i have to update the map.
But this is an inavoidable thing. During development there'll be old assets noone uses for the official maps anymore, so they're deleted because the installer should be as small as possible.
Third party maps using the content have to be updated.
I'd suggest to all the server owners to check the maps for errors previouse to hosting them on their servers and not host them if they are affected.
Otherwise the broken versions will spread to the community and the mapper has to rename the map in order to avoid "map differing" issues.
For all those maps that won't recive an update, it might be a good idea to have the original resources downloading seperatly from the server using .res files.