I think this also speaks to the value of intelligently-handled "bonus" content. Having the Warthog, Armadillo, and random items from games such as Sunset Overdrive (in addition to the free DLC) was a definite factor in my purchase since I got the PS4 version for free.
Super Time Force did the same on PS4 (add some Sony characters) which also made a lot of sense. We'd all be in better shape if the exclusive content we got was actually tailored to the ecosystem (and thus would never be on the others anyway) instead of "Thanks for the marketing, here's another 20 minutes of side missions we cut out of the other guy's copy!". Hell, go one further with the Soul Calibur II route and give
every version something unique. You make people happy, and you will sell multiple copies to the hardcore fans.
One feels like added value, the other feels like you're paying the same for less. Rocket League, ya dun good.
Proof that the parity clause MS used to enforce was stupid.
The "parity clause" also included "hey, if you're late on our console, can you give our gamers a little something extra?". Guess what happened here and was likely a factor in its success?
The Phil said:
If another platform does a deal with you as a developer to build an exclusive version of your game for them, and you can’t ship on my platform for a year, when the game comes out in a year let’s just work together to make it special in some way.