Not all two-doors are coupes. Most of the examples show here are sedans, not coupes, which have a shorter roofline, and often only seating for two. If a coupe had a back seat there was usually less leg room, sometimes they had rear fold-down jump seats. The '32 Victoria is technically not a sedan or a coupe, it's a Victoria, a closer-coupled type of sportier two-door that was common in the '20 and '30s.
For decades manufacturers offered coupes and two-door sedans...
'51 Chevy Styleline Club Coupe
'52 Chevy Styleline Two-Door Sedan (note the longer roof on the sedan)
Chevy also offered the Fleetline fastback as a four-door or two-door sedan...
Incidentally, most of the cars people incorrectly call "two-door posts" are properly called sedans. Some are coupes. Depends on the length of the roofline.