Is the term "4k mastered" a new marketing gimmick for 4k tv owners?

I've seen this for Ghostbusters. They've got a new bluray edition that says "4k mastered". Of course a bluray isn't 4k.

I do understand the importance of starting with a high quality source. I know some of the early bluray releases were just really upconverted dvds essentially and not done as well as they should have.

However is this just more smoke and mirrors to get people to rebuy the same movie again and again?

Or is this a bluray version of those superbit dvds that eeked out as much bitrate as they could on the platform they used?

Otherwise to me it just seems like marketing bull.

So whats the real story for a bluray that states its "4k mastered"?

--- Please note I don't even have a 3dtv so 4k is quite a few years down the road for me, if ever if it becomes a passing fad like 3dtv sort of is now.

Edit - here's the edition I"m talking about at amazon:

http://www.amazon.com/Ghostbusters-Mastered-Single-Disc-Blu-ray-Digital/dp/B00BPA2PBG/...s=ghostbusters

Edit 2 - and whats this expanded color stuff? Is that more trickery?
Expanded color requires xvYCC-compatible TV and Blu-ray player