More likely that Amazon and Play dictated this replacement scheme to CBS/Paramount. Amazon in particular is powerful enough these days that if you piss them off and they then refuse to sell your product it could well cripple your products prospects in the market.
Pure speculation though, I may be completely wrong.
I doubt it. Amazon US isn't offering complete replacements. Why should they not "dictate" the program to CBS in the states? And, as many other posters mentioned, this kind of replacement scheme doesn't happen very often, certainly not in the UK. It depends on the distributor, in this case Paramount UK.