IT hobbyist here. This guy knows his stuff. Dangerous attacks are the ones that are very low effort with medium to high reward. This attack is high effort and low reward. This is one of these trivia things, that you will virtually never see in the wild.

While I appreciate your refusal to spread panic, would you mind explaining what the attack does and why it's a nothingburger, maybe even why it's not practical? Because right now, you assert a lot of things without any explanation.

Not saying you're wrong, but I think it's good practice to not just rely on claims of authority

It’s also worth considering the Signal threat model: a contact you communicate with is not considered an adversary. You can choose not to accept an initial message request.

I believe Signal has already fixed it, while meta said they won't fix this in WhatsApp.

This side channel can be used to infer more than a rough timezone, specifically, an attacker could continuously monitor :

• the number of devices linked to the target’s account, along with fingerprints that allow differentiation between operating systems and browsers
• the locked or unlocked state of the target’s phone
• whether the phone is connected via Wi-Fi or a mobile network
• whether the WhatsApp application or browser tab is running in the foreground or background.

In addition, an attacker could deliberately drain the target’s phone battery and consume their mobile data allowance

I've tested this on myself and can confirm all of this can be done reliably