I'm sure they will but they won't be trading it back or returning it to TRU as it will be a prorated return value of $35 for each game. I suppose if you wanted to pay $35 for a game and $50 for the GC you could return one game back to TRU.
As far as trading games back to Best Buy or Gamestop or reselling them you get that talk in just about every thread but assuming you'd have to get $35+ to make it worthwhile I know the comments won't be nearly as bad.
Hell the first dozen or so posters didn't even realize this deal has more value added then a B2G1 free
Well, to be fair, you don't know how they'll handle the receipt. The GC may ring up as free while the games are full price. If that happens, people will definately be trying to exchange games the following week.
And how does it have more benefit added than B2G1? I can see some small benefits (that I mentioned above) But I don't think they outweight the additional cost ($10 more plus tax on the third game which wasn't charged before), the fact that it won't work for 3DS or Vita games, or the fact that that you can't do it with $30 titles.