This alone obviously doesn’t put Windows in danger, but if it does go over well then it’ll mark a turning point; A large non-techy institution getting away from Microsoft’s castle and being better off for it would signal to the world that it’s not only doable, but could even be worth it. It’ll take a while, but this could be the start of the end for Windows.
That "significant danger" was a bit of dramatization on my part. I don't expect anything to significantly change in the short term. I was more referring to long-term tidal-like change, which would be very hard to stop once momentum builds up.