This was a feature in the past, but the first developers who implemented it did not take into consideration the limits that Twitch has on their API, so it was abusing it. Twitch only allows us to pull 100 subscribers at-a-time, and their current limit is 1 API call every 1 second. So, let's say you have 1000 subscribers it would take 10 seconds to pull all of those subscribers, but it can't only be done once since we need to check if someone unsubscribed. During that 10 seconds your computer will be doing a lot of work also. Also their API is known to be unstable, like this week the chat list API has been down, so all the bots who use it, which is a lot, have no idea who is in the channel. We removed it a long time ago.