(This is my own personal opinion and not an official answer in any way)
Practically speaking you shouldn’t run into any issues as long as you are only joining and logging/analyzing data from channels with explicit permission from the channel’s owner. People tend to really freak out when a bot is sitting in their channel that they didn’t invite.
In general the implications of the ToS on chat aren’t very clear. I’m of the opinion that when connecting via IRC it’s considered part of the API which is basically designed to be accessed by some automated means.