In earlier news posts in late 2009, Aftermath would eventually start offering individual maps that were in previous Aftermath installs outside of Aftermath. This is also the reason why all the older maps wont be found in the forthcoming release AM2010. The first off-load of maps begins with the very first Borg Co-op Wave map ever created in the Legacy community: Grid 453.
However, rather than just packing the map up and shipping it out, the map itself has had some extra work done to it to freshen it up for its solo release. The lighting was changed and the background was swapped out for a more conventional one that fits the tone of the map.
At this stage, there are plans to off-load existing maps throughout 2010 either as an individual download or in packs. More closer to the release of AM2010 a series of booster packs will start to filter out containing the older material that wont be present in the major release.
These releases have the intention of having maximum compatibility with any other mod within Legacy. Just simply install the maps and they are ready straight out of the box. There is no set release schedule for the offloads but there are quite a few maps that will eventually be up for download.
The additional maps can be found in the Add-ons section of the Aftermath Legacy page or by following the link below