Generally all the releases get cloned to
https://github.com/raspberrypi/linux/ and the required Pi-specific stuff merged in, but Raspbian will tend to stick to a kernel release that has LTS from upstream. Some distros (eg OpenElec IIRC) will adopt the absolute latest and greatest kernel version, but they also then hit a few snags.
Seeing as it has been announced 4.14 will be LTS once it has been completed (it's not even started yet), it is fair to say that it will be adopted once it is all stable.
Software Engineer at Raspberry Pi Trading. Views expressed are still personal views.
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