Hi Carlos,
yes no problem with running CGSE+ in a chassis with 140G fabric cards (CRS-3).
With 140G fabric, chassis -A or chassis -B makes no difference, all line cards are capable to run up to 140G (40G or 140G depending on their generation).
I don't think you'll find a written statement specifying -A chassis. But in the datasheet, http://www.cisco.com/c/en/us/products/collateral/routers/carrier-routing-system/data_sheet_c78-728175.html you'll find "Chassis compatibility: All current Cisco CRS-3 line-card chassis"
Cheers,
N.