These are still 1-click, not zero click. So the best protection you can have is not opening unknown files that were sent to you. That being said, lockdown mode blocks all sorts of message attachments. From the videos it look like they are using pdfs in the messaging vector, which would get blocked too. So you would be safe-ish. But lockdown mode is so restrictive that it doesn't really make sense for most users. Or at least it doesn't make sense to buy a $1500 phone and then limit yourself to something you could have gotten for $50.