You'll also have the option to mute topics, so you won't have to risk spoiling a show or enduring a done-to-death conversation.
The test is currently limited to Android users and includes a companion test that lets you create separate lists to follow individual interests, including keywords and individual users. If you know someone always has a good hot take on politics, you can keep tabs on them in addition to mentions of the relevant issue.
And yes, there's still another test after that. True to rumors, Twitter is testing an option in Android to snooze notifications (see below). You're limited to one-, three- and 12-hour increments, but those could do the job if you're popular enough that your phone tends to blow up with mentions and DMs while you're out on the town.
None of these are guaranteed to see a widespread release, but topic following stands a better chance than most. Twitter's perpetual challenge has been to help newcomers decide who and what to follow. This would get the ball rolling even if you have no idea who's worth watching. It could also be considerably more convenient than diving into Moments, which exist as separate entities disconnected from your own feed.