(Opinions are my own, I have no inside knowledge.)
I vaguely remember hearing that P2P Skype was the bane of sysadmins' existence. Skype would elect clients on high-bandwidth networks as supernodes. This tended to be business customers - the very organizations MS wanted to attract. Skype's prodigious hole-punching ability made it difficult to throttle, so it got banned from a lot of enterprises. MS essentially hosted the supernodes on Azure, which centralized it.
As for encryption, on the other hand, Wikipedia says MS specifically added the ability to eavesdrop for law enforcement agencies, though apparently Skype had already added a backdoor for the NSA before MS bought them: https://news.softpedia.com/news/Skype-Provided-Backdoor-Acce...
This [1] is one of my favorite leaks from Snowden revelations, and I regularly bring it up anytime people try to downplay what PRISM is. That's a user manual for NSA agents on how to spy on Skype users (including video and text) in real time. It's informative and also amusing at times. For instance in the FAQ one issue a confused spook might run into is why they're being spammed with the same messages repeatedly. It turns out that when a user logs on to a new device, the recent messages Microsoft sends to the user are also directly forwarded to the NSA, which can result (from their perspective) in messages being repeated.
I vaguely remember hearing that P2P Skype was the bane of sysadmins' existence. Skype would elect clients on high-bandwidth networks as supernodes. This tended to be business customers - the very organizations MS wanted to attract. Skype's prodigious hole-punching ability made it difficult to throttle, so it got banned from a lot of enterprises. MS essentially hosted the supernodes on Azure, which centralized it.
As for encryption, on the other hand, Wikipedia says MS specifically added the ability to eavesdrop for law enforcement agencies, though apparently Skype had already added a backdoor for the NSA before MS bought them: https://news.softpedia.com/news/Skype-Provided-Backdoor-Acce...