Thread:BEJT/@comment-35644362-20190724013345/@comment-26838855-20190726075124

We try not to make assumptions. There's no hard and fast rule, but basically if the other film clearly exists as an implication, it's worth putting, but if not, don't.

We don't add sequels to a film that was referenced, because there's nothing to suggest that any further films were made in the MCU. So just because The Force Awakens exists in the MCU doesn't mean we know Rogue One or The Last Jedi do for sure.

Since How to Train Your Dragon 2 is called what it is, it is clearly the sequel to How to Train Your Dragon in the MCU as well, so yes, you can be sure that How to Train Your Dragon came out. That can be added.

Sequels that are less direct in nature or title can't necessarily assume previous films. Using The Force Awakens as an example again, it doesn't mean we can assume that the prequel trilogy was released in the MCU.