I think until its beta build for windows we can't extect we will have it. W8 until official release of 2017.1
At least for the last release, there was a rather long delay between the Windows release of the first build for the version and the Linux release. After that the versions tend to come relatively closely together. I assume there is some level of crunch for the final Windows release and first beta version, and so the Linux editor gets pushed back. Edit: Actually, the 5.6 release was simultaneous, it seems. I must be remembering the 5.5 release, which looked to have a gap of around two months (https://blogs.unity3d.com/2016/08/30/get-the-unity-5-5-beta-now/ vs https://forum.unity3d.com/threads/unity-on-linux-release-notes-and-known-issues.350256/#post-2772944). That release was apparently the release that moved to a unified codebase, so it may be that which caused the delay. In this case, it may be the new .net version requires more legwork to port than most features - at a guess. I am, however, eagerly awaiting this version - currently my tooling is in an awkward state due to needing to support Unity's old .net version. The new beta would solve a lot of my problems (and just make development a lot nicer in general). There is a Windows beta for 2017.1, in fact there have been a few versions. Historically the Linux editor beta has been released in sync with the Windows beta, and you have not had to wait for full releases.