With emails coming in from multiple places, often advertisements are mixed with scams, sadly, not all scams get caught by Thunderbird, but with a folder option to "High Security", would make folder act like everything is "untrusted".
Basically a "High Security" folder would restrict much like the Spam folder does, with the exception that everything about the message will be restricted (ignoring pre-approved sites).
So when people use filtering to move a message out of the Inbox, into a folder for say "Facebook" or some other social media, they're not going to hit a scam email that looks legit and isn't caught by Thunderbird, because the links and exterior content will be blocked, unless the user agrees to unblock *just* that email for that one time. If the user goes to another email and then back, the unblock would need to be done again.