But if you read what follows in the same message,
So for CO users: @CBA;@CBA_A2;@CBA_OA
You do need the three of them, and yes there's been a major update, and it did change the way you need to use CBA.
The new version supports the various game editions better (A2/OA/CO, TOH, TOH Rearmed(A2/OA/CO). UI inheritance and dik_codes.h includes and different locked script command behavior, see posts of past pages for more details),
removes various CfgPatches and CfgVehicles ghost classes that were existing before in A2 or OA Standalone incl wrong UI inheritance, and fixes several issues.
Review the changelogs and ticket/revision history on dev-heaven for details.