I doubt it, E2E isba huge part of Whatsapp's selling point considering it's exclusively a messaging app. Instagram is primarily a social app with messaging features.
Normal people don't choose a messaging app based on E2EE but based on whether their friends use it.
"Your security code with X changed"
"What's a security code?"
> Probably Whatsapp is next, if it isn't quietly already.
And I will be pushing to remove WhatsApp if that’s the case.