I'd like to know how many people is following my post. Where I can know it?
I don't see what's wrong asking such question in the public community. Perhaps what you are trying to accomplish is internal business, but you are most likely going to get better answers from experienced users here in the public community than elsewhere.
Jive 8, the current platform can display what people follow a forum space or social groups, but does not provide such info for posts. People have actually asked similar questions at the vendor's product forum at https://community.jivesoftware.com/community/developer
I think it is fair to say that community management has high hopes and plans for the new platform, but success and accomplishment have yet to be seen once people give feedback. As such, there probably isn't much of a point to worry about the current platform, which is all going to be water under the bridge in a few months anyway.