Not if the agreement upfront is "I can say what I want, when I want, on any schedule I choose, on any medium or mediums I choose, to whoever I want. The good, the bad, and the ugly."
I have nothing on the line here, I don't do product reviews for a living and if Microsoft never sends me another thing ever again because they didn't like what I had to say about their products, then they have more to lose than me (mainly because their product has flaws and they'd be essentially stating the flaws aren't worth fixing, which is 100% of the problem Apple dug itself into a hole with over the past 2 years).
I have nothing on the line here, I don't do product reviews for a living and if Microsoft never sends me another thing ever again because they didn't like what I had to say about their products, then they have more to lose than me (mainly because their product has flaws and they'd be essentially stating the flaws aren't worth fixing, which is 100% of the problem Apple dug itself into a hole with over the past 2 years).