Let's step back a bit. There's a software product in use today that embraced an open standard, extended it and in doing so "extinguished" other implementations in a way that has much greater implications for software development (especially in the present tense) than anything Microsoft ever did.
What product am I thinking of? The GNU C Compiler, of course! And the GNU tools in general (which have thoroughly "EEE'd"[0] competing POSIXes), while we're at it.[1]
If "SSO" or "EEE" are "actionable unfair competition," then whoever is the current owner of the Bell Labs IP has every right, and every monetary incentive, to get the whole GNU/Linux ecosystem shut down.
[0] "EEE" isn't bad! You could just as easily call it "beating the competition by making a product with better features."
[1] Assuming you agree with me that compiler lock-in and operating system lock-in have greater implications for software development than for example web browser lock-in.