Well, since an Admin has now spoken up, I'm guessing the unanswered questions mean there's no news.
Not necessarily. The GMC is a community run forum, so YYG staff need not be obliged to answer every question raised here. If you are looking for any official product support from YoYo Games then please make use of the official
YoYo Games Helpdesk as questions can easily go unnoticed on such a large community. But the question that you (and
@AndrewCampbell) wanted an answer to has already been covered by the official
Road Map -- GMS 2 will come out of Beta in Q1, 2017 prior to the release of the Mac IDE Public Beta.
How does it work with publishing on all platforms? If you buy GMS 2, will you be able to publish on android etc.?
Yes, if you buy the Mobile export modules. If you want to publish via GMS 1.4, then you'll have to buy the Android export module
now as GMS 2 will come with a GMS 1.4 Professional license -- Windows, Mac and Ubuntu being the only available modules by default. Simply buying the Mobile exports for GMS 2 will be a better way to go.
If you buy the master pack for GMS 1.4, do you get tools to publish for android on GMS 2 when it comes out?
You'll get a discount on each product, but you will still have to pay for it. Buying GMS 1.4 Master now just for the sake of getting a discount isn't worth the trouble. So get the modules that you need for GMS 2.