The bot is "in plain sight", and can be kicked and banned by ops. That's a major difference. Further, the bot is only given the ability to eavesdrop when enabled by authorized participants (e.g. it was either invited or not kickbanned by people who could see when it joined the channel).

The visibility and lack of expectation of privacy creates a very different situation. If this "MS bot" showed up in your conversation and said "hi, I'm going to visit every URL you post unless you kick me off this conversation", it'd be a very different situation.