I had an '08 Mazdaspeed3 that I used as a daily driver and I never did anything to that car until I traded it in at 54k miles on a new '11 Platinum EB. It drove just as strong the last day I drove it as the first. I never seafoamed it, replaced spark plugs, NOTHING but drive the heck out of it. I did use mostly premium Shell for gas and Pennzoil Platinum / Ultra for oil on 4500 mile oil change intervals with Mazda filters. 2 air filters rounds out his maintenance program. Surely Ford monitored this engine and learned.

Besides, if decarboning is needed, I'm sure Motorcraft will develop some sort of sea foam product that blow all that stuff out.

VWAG may be having a heck of a time with their engines, but I haven't heard much from the BMW camp about carbon deposits - their engines just chew up the high pressure fuel pumps with alarming regularity. My younger brother had a 335i that virtually liquidated his driving license with points before he had to get a car that was less of a party. That car never gave up; his license did! 55k on it.
We'll see how this plays out, I have 2 Ecoboost engines here; an FX4 and a Platinum, so you know I'm in!
Cheers!