However, the distinction between Imperial I-class and Imperator-class is fuzzy, because Wookieepedia states: It features two hangars, one on the starboard side, and one on the port side, although, only the port side one is usable in naval combat. The Imperial Star Destroyer, also known as the Imperator-class Star Destroyer, is an Imperial starship featured in Star Wars: Battlefront II. In particular, the Battlefront II wiki page about ISDs states:
Their response was that the model is based on canon information indeed, and is modeled off the ISDs from the Battlefront II video game. So as a good nerd would do, I confronted some of the event staff about that minor detail of Star Wars canon (because, let's face it, we love having that kind of conversation). At least, I'm fairly sure that the Imperial I-class, the Imperial-II-class and the Victory-I-class SDs have only ventral hangar bays, according to the information available to me on the Wookieepedia. Now, given that I spent quite some hours of my youth playing the 1993 X-wing videogame, I know for certain that ISDs have ventral hangar bays, and not lateral hangar bays. (Unfortunately I haven't been able to find any publicly-available wide shots of that model showing the position of the lateral hangar bays)
and 4(!) lateral hangar bays, big enough to hold squadrons of TIEs or a YT-2400 freighter: Now, that model had both a ventral hangar bay big enough to accommodate a CR-90 "blockade runner" Corellian corvette. A bit of background: I recently attended JEHES XVI, a Star Wars-themed event organized by HoloRed Sevilla which featured, among a lot of other things, an impressive 2ish-meter-long cardboard model of an Imperial Star Destroyer, which can be briefly seen in this summary video montage: