The pack just adds (mostly) vehicles to CMBN, including "funnies" like Sherman Crab and Churchill AVRE, as well as man-portable and vehicle-mounted flamethrowers. Also, AT bunkers, Kangaroos, some on-map artillery, etc. etc.
The contents of the pack are great, but the release seems a little weird - there are no scenarios or campaigns with the pack, so they are for quick battles or use scenarios only.
I think the problem is CM Helper is confused by the new installer work that was done by BFC. From what I understand CM Helper looks at various installed files (.exe or .brz not sure which) to figure out what you have installed. However the new install process from BFC installs everything with the intention that in the future those that have not purchased the vehicle pack can still play using vehicle pack toys if they are playing against someone who did by the pack.
So bottom line CM Helper will need to be updated to figure out how to tell what you have access to or not.