How long ago was it that Mikrotik shipped devices that listened on the WAN port? The Mikrotik hEX and RB3011 I bought last year most assuredly was not configured that way even though the version of ROS on them was many revisions out of date.
I've purchased a rack-mounted RB2011 and wAP ac, more commonly known as RBwAPG-5HacT2HnD (lol these model names), within the last 3 years that did not have firewall enabled and contained no firewall rules by default. If I had to guess it was around ROS 6.32 or 6.33 release for 2011 and recently for the wAP.