All maps are removed for a certain reason.
There were a lot of maps around around the time that these maps existed due to the large amount of accepted maps created by community members.
There were over 40 maps back then but this isn't always a good thing having lots of maps, as it is harder for your favourite maps to appear.
Also a lot the maps had similar layouts and designs, there needed to be some creativity.
As result, a lot of the maps were redesigned and some were removed.
Some reasons why Atlantis and pirates were removed:
Pirates (Solo)
- The starting islands were unfair and unbalanced, some players had much bigger advantages than others
- The layout favoured some islands over others
Atlantis (Solo)
- Another alright map, just didn't feel it was good enough to keep, it wasn't a map that stood out due to having the same boring layout as a lot of the other maps.
You can always hope or suggest a revamp but the chance that this will actually happen is not that big, I shouldn't count on it.
The maps are probably not coming back in their old state.