Instagram is rolling out a new option to combat on-platform abuse, this time focused on limiting actions from groups of users, as opposed to muting or restricting individual profiles.

As you can see in this example, posted by Ahmed Ghanem (and shared by Matt Navarra), some Instagram users are now seeing a new 'Limits' option within their Privacy settings, which enables you to temporarily limit unwanted comments and messages from selected groups.
Instagram says that it will recommend groups of accounts that you may want to limit, based on detected activity, which will then enable users to hide interactions from these users unless they manually choose to see them.
Navarra also shared these screenshots of how to set up your chosen limits :

As you can see here, you can specifically choose to limit interactions from accounts that don't follow you, or new followers, which could help to reduce the impact of those looking to join a pile-on, as a result of you being 'cancelled' or similar.
Which has become a more common occurence, and it can be surprisingly easy to inadvertently step into a misinterpreted attack or criticism, which can see the dreaded 'Cancel Culture' gaze switch to you, for your fifteen minutes of internet infamy.
And even if you do make a comment which you know will spark a response, the sudden amplification of attention can be a lot to take, so shutting down, or limiting those mentions, can provide a welcome relief, enabling users to lessen anxiety and stress.
Instagram also added a 'Restrict' option back in 2019, which similarly enables users to limit the comments of certain users by hiding them from your view.

But as noted, that's focused on reducing the impact of individual users - this new option aims to limit 'brigading', where groups of people rally together to target an individual.
We reached out to Instagram for more info on the update, and it provided this statement:
“We want to give people more ways to manage intense instances of harassment or abuse. We’re testing a new tool that lets people hide comments and DMs from recent followers or people they don’t follow for a certain period of time.”
So, right now, this is just a test. If you're part of the test pool, you'll see the option in your Privacy settings in the app.