I see what you mean Julius.
Anyway, I'm not familiar with WPSiteSync and I also do not know of an extension that can do that in Joomla.
The best thing you can do is to search on Google or open a new discussion in the
Official Joomla Forum.
In my 9 years experience with Joomla I've never heard of such thing.
I've always been updating the localhost/test/development installation first and then doing the same with the production/live installation.
Yes, it means that you have to do the same thing twice, but after all those are two completely different/independent installations with different databases, etc.
I don't know Julius, it would be great if you can find such an extension, I'm just not aware of such thing and cannot help you here.