I can confirm this. Both 4004 and 4096 are at Grand Ave, however in the system 4004 is still listed at YU. 4096 is listed at GA. In addition, based off of the roster on google docs, the following buses are also at Grand:
-4244
-4331
-4443
-4449
-4522
The Jamaica - ENY LFS -RTS swap has begun folks:
-8094-8101, 8104-8105 to JA from ENY
-4918, 4921, 4926-27, 4930, 4968, 5000, 5013, 5019 to ENY from JA