I don't know. I think that users being able to harmlessly deactivate their Threads account but not delete their profile is evidence against that hypothesis. Surely the ability to delete something is one of the most basic features? All the more so if Threads just depends on Instagram for auth.
My bet is that the decision to not allow the user to delete only their Threads profile has been fully intentional. The last thing Meta wants is for the fleeting users who quickly jumped on the latest Threads fad to eventually delete their profile once they become bored. That would be embarrassing to Threads and reduce its sticking power if it were a common enough phenomenon. Much better for them to keep the users' content hostage under their desire to keep their Instagram account.
Its absolutely this and I am shocked at the amount of people coming to the defense of Meta here, like, its not users' jobs to figure that a new app is actually the old app but in a different skin, and merely saying "an Instagram app" wasn't clear enough in obviating it was the same social media account. That's on Meta, not on users.
My bet is that the decision to not allow the user to delete only their Threads profile has been fully intentional. The last thing Meta wants is for the fleeting users who quickly jumped on the latest Threads fad to eventually delete their profile once they become bored. That would be embarrassing to Threads and reduce its sticking power if it were a common enough phenomenon. Much better for them to keep the users' content hostage under their desire to keep their Instagram account.