> I'm asking if the free Player version is going to get continued to be updated so it supports modern Linux guests
Your original question (and my response) seemed to ask specifically about Unity with regards to Linux. As for more general support of new/future Linux versions my assumption would be that will continue (but that's just my guess as a random engineer in a completely unrelated business unit, you may want to reach out to the Workstation team via Twitter/Facebook/forum for an informed and official answer).
Not really (also, post-7 Player has been re-branded "Workstation Player"[1], presumably so the relationship to Workstation is clearer).
[1] https://www.vmware.com/products/player