You're overlooking that bricking the device may be illegal. If it is to have an expiry date, it should be printed on the product - all radiation-based smoke detectors already have this.

Bricking the device remotely may be a criminal offence if it's not specifically permitted in the EULA. And if it is permitted in the EULA, that term may not be enforcable. And if it is enforcable, then all consumer reporting/review organisations should point advise you never to buy the product.

Certainly if one of my devices got remote-bricked I'd be taking legal action.