The following behavior occurs in all folders, and this may very well be an unintentional bug or design flaw/oversight:

Clicking the "Delete" trashcan menu icon when selecting multiple messages (as well as clicking the "Delete" trashcan icon next to a single, individual message) will produce a confirmation/warning prompt as is normally expected and industry-standard.

However, pressing the Delete key on the physical keyboard does not produce a confirmation/warning prompt; the delete action simply goes through. Considering there is no Undo option after completing said action, this is extremely risky! This is especially undesirable in Spam and Trash, where pushing the Delete keyboard key now permanently deletes messages without warning or final confirmation. There is no grace or leeway for human imperfection, and important messages can now be permanently erased/lost too easily due to one mistaken keystroke.