Unity 2017 not tested on OSX 10.9.5???

I'm a bit worried about the new Unity 2017. It doesn't look like it's been tested on OSX 10.9.5 and below despite it saying it is compatible with these machines. Particularly things like video textures and the timeline seem to make it crash.

Now I'm afraid to update my OS because if I build a Unity app on OSX 10.12 it might not work on OSX 10.9.5 and crash for those users.

I wonder if Unity has a test suite which tests things on different OSX versions? Because it seems like it hasn't been tested for this versions.

Admittedly, there are less users of OSX 10.9.5 and below but this seems like a big issue of whether you can trust Unity to work on the operating systems it claims to work on. Of course we should always test apps on all operating systems ourselves. But not everyone can do that.

I am trying to find all the places it crashes for OSX 10.9.5 and send the bugs to Unity.