Couple of things.. Yes oil does play a significant role however the reason why the US has concentrated efforts in the ME has a lot to do with 9/11 (Al Queda) and our close ties to Israel, Jordan, SA etc. Those things will remain pretty much the same regardless of energy independence of the United States.
US had large footprint in the ME way before 9/11, mainly to secure US and Western energy access. Fracking technology will enable US to be energy independent, and that's a game changer. The US military will still be present in the ME, but probably less so after energy independence.
While the war in Iran and Afghanistan is tapering down, majority of those forces are land forces. Naval assets will for the most part remain relatively the same or just very minor reduction in that region. Military warplanners are very aware of the still constant instability in the ME and the recent crisis in Syria to not make any drastic reduction or move any significant naval or air assets from that region anytime soon or even in the near future. IMHO if POTUS, Pentagon etc moving any air and naval forces away from the ME would be a very idiotic move unless we totally want to wash our hands off that region altogether which is not realistic.
Very doubtful USN will retain same force structure after Iraq and Afghanistan, because we're downsizing our military, while at the same time re-balancing to Asia. There's simply not enough ships, planes, and personnel to do both.
As to forward deploy CSGs you need a relatively large base with the proper facilities, maintenance the whole she bang and until China has such a facility a fwd deployed CSG in the mid east would not practical. I may be wrong but I don't think PLAN has anything like that or even similar to say NSA Bahrain, Doha, Kuwait Navy Base / Camp Patriot, Camp Lemonnier etc. Basically to be have a permanent fwd deployed group you need a rather large port, an accompanying airfiled and prefably a Marine base or two on it or at least relatively close by within a couple hundred miles and obviously a local population that is relatively 'friendly' to your forces.
I did mention 2030, right? Assuming China continues her path to the world's largest economy, and assuming she doesn't provide a whole lot more public goods for the global commons, she will have the money, resource, logistics, and know-how to have multiple CBGs, some of which could be stationed in the South China Sea.
Of course with all that being said with the amount of economic dependencies and transactions that China has with Africa it is not unreasonable for them to lease land etc, share naval bases or start constructing a major naval base on that continent sometime in the future but that's all more political maneuvering than actual military.
PLAN base-to-come in the Seychells is only the beginning of more global political and military engagements in the future.
