I can almost guarantee the TSA will invest zero dollars or time into deciding which MacBooks are okay. This is Apple's problem to solve. Zero time, money or attention from the TSA or the airlines will be invested. If the FAA bans any Macbooks, all "Apple looking thingies" will be effectively banned.
Source: 3 decades of govt and airline experience.
Advice: Buy a Dell sticker to cover the apple logo on your MacBook. Or some similarly silly thing like an "Apple Store FAA compliant sticker" program. (I'm linking back to this comment later when it happens :)