There is a chance that a escape hatch is being tested for users who don't want to be part of a thread. Jane Manchun Wong, a writer and researcher, posted a picture of a new feature on Friday. The feature would prevent people from mentioning you in a conversation again, and it would also stop you from receiving notifications about it. You can still see the thread.
The feature looks different than the option that turns off notifications for threads mentioned in. Leaving the conversation will make your handle appear as plain text in the message where you are mentioned, rather than the hyperlink someone would normally see if they tap your handle. That could make it harder for other users to pull you into conversations and make you not want to participate.
The feature is being tested in an email, but it was not confirmed whether it is. The company has introduced ways to control how other users interact with your account. There are changes that simplify existing options, like forcing a user to unfollow you, as well as limits to replies and notifications when an account with lots of followers has retweeted you. This feature would fall on the more dramatic end of the spectrum, but also add an option a lot of users would appreciate.