Should Neutral and Earth be bonded at the meter instead of in the main panel(s) with tandem 200A main panels
In my neck of the woods (Pacific NW) we call that a "class 320" service:  A single meter feeding 2 main panels. Because both panels are considered main panels, neutral and ground need to be bonded together. In the meter panel, in most cases, the neutral is already bonded to the can just by how the lugs are attached. I recently installed a class 320 service on my son's house that did have a "service bypass" that would enable the power company to swap a meter without interrupting service, but I don't think that is what you have.  A pic would help. 

2020 code is requiring the ability to cut off power to a structure externally.   That may have been required locally for some reason back in 2014...local codes vary.