Fixed, most probably. But improved, definately yes.
I used to only be able to record 4K for less than 53 secs. Now at 1 min, it barely feel warm. I manage to record in 4k up to 5:43 min. That's 5x more than it originally could. At least for my phone that is. And recording at the same location.
But some will definately cry foul because 5 mins is not enough. Well, don't record in 4k then. Z2 uses software encoding, not hardware encoding unlike a proper 4K Videocam. On those devices, you can record them as long as you want. And this applies to other 4K video capture capable smartphones from other brands as well. This is a limitation to the current technology at this this time.
If you want to use Z2(or other smartphones) to record a long 4k movie, you better have a proper cooling systems. If not, get a proper 4K videocam.
