It can go both ways
From what i see in mid-sized companies making up our customer base is that all have quite large windows farms, and a few Linux systems, mostly for databases en websites.
Roughly it is 95% Windows and 5% Linux systems. Within these companies, there is a wild variation in Linux distros of all sorts and ages. With the rudimentary Linux support in both HyperV and probably also Azure, most of these platforms won't run.
In Europe the market and decision making processes are such that it is probable that these mid sized Microsoft shops might decide for Azure, after all, who gets fired for choosing Microsoft ?.
With this scenario, the 5% Linux will just disappear, because MS won't stop FUD-ing these customers and in the end they will give in and shell out a few thousand for MS server cals to replace Linux.
So if MS manages to gain significant market share with both HyperV and Azure, then Linux will be slowly strangled, causing it to go extinct in the data center of mid-sized companies. From a market perspective, it would be good if the European commission will watch this closely, it is strange if a company dominant in OS, becomes dominant in virtual machines too, then we are back in the 70's where 75% of every dollar spent on IT went to IBM.