Instagram is enabling users to create their own "Add Yours" templates in the app, offering another path for engagement on specific parameters chosen.
You can now create reusable versions of your Stories formats. That's allowing you to build out custom quizzes prompts, etc. using tools that already exist in-stream.

According to IG:

"People will be able to design and share their own custom, meme-able Add Yours templates by pinning GIFs, text, and gallery images to a Story template. Add Yours story templates give people more ways to express themselves in stories and share what's on their mind with followers."

To create an "Add Yours" template you will add any GIFs, text, or images that you would like to feature in your Story. In this case from the sticker tray you will select "Add Yours Templates," and then choose what elements you would like pinned to the Story as part of the template.

You can also pull templates from Instagram, either to use directly or to get inspiration; you can make those by tapping the dice icon at the bottom of the composer screen .
From there, you can post it in your Story, with that Story then then showing an "Add Yours" prompt, encouraging viewers to add their own take on the same.
It might also enable Instagram to access an entirely new class of trends: Just think of enabling its billion-plus users to create their own templates, which is bound to mean all-new prompts and engagement options come out.

It's a fascinating concept, though it's not as simple to come up with interactive, engaging Story prompts as you'd think.

But if this results in just one viral trend, then that's going to be worth it, and I think it will.

The new "Add Yours" feature in the updated app.