RAND !== F/OSS compatible

I would like to be optimistic, but decades of history of Microsoft's actions make me cynical.
The problem is, what does "non-commercial distribution" mean?

I suspect in practice it will mean that Microsoft will want payment for every installation of
(just for example) Red Hat Enterprise, as that is a "commercial distribution".  

Microsoft might even define "commercial distribution" to cover Fedora and Ubuntu, since Red
Hat and Canonical both are for-profit companies.

In short, the "covenant not to sue" seems very suspicious unless it covers all open source
code regardless of (a) how it is distributed, and (b) who is "behind" the distribution.