That depends. Either way, PC already has Forge which is quite a powerful API and i think Mojang realizes that hence why they aren't doing anything in that regard. Atleast noting official. Basically, if it ain't broken don't fix it.
To be frank, Forge is more than likely doing a better job than those at Mojang could do.
I think this is most likely correct. I think the good thing about them at least thinking about modding and an API is that it caused them to consider those things when coding new content and when revamping old code. This has made what Forge is doing much more possible.