Since it was raised, I went in and asked them about it...
The main reasons:
- Bright coloured Store versions - "pop out" to parents and young kids more, who will buy more units than the older gamers or dedicated collectors, in ANY colour.
- SDCC gives Hasbro the opportunity to get the game-colours to fans early in some fashion, even if it was a limited release. Otherwise, options are limited until a late wave redeco, or a store exclusive down the track.
Here's hoping they don't sell out at SDCC, so that we can get some from the Hasbro online store to avoid paying ebay scalpers.