I would assume they will have added a new set of settings or an app for lease providers that gives them the ability to perform these actions on registered phones.

There’s no reason to assume that just any old third party will be able to brick your phone that you bought outright, any more than there already was - which there wasn’t.

It’s just straight up fear mongering. It’s like saying that a work issued and managed laptop being able to be wiped remotely if lost means everyone should be scared that their personally bought laptops can be remotely wiped by anyone at any time.