Thanks @zhangxm. Cocos2dx download includes some precompiled binaries, like for libjpeg and libcurl etc. In older version of cocos2dx these precompiled binaries were not there for all platforms, but I checked and now in new releases cocos2dx already has precompiled binaries for all 3rd party libraries for arm, arm7a and x86.
So, yes, now developer can set any values for their application. For default template I think compatibility matters more. I suggest either armeabi only, or all 3 for both speed and compatibility.