As we're using this thread as kind of a spoiler thread, let me specualte about the 3 DLC remaining waves:
Wave 2: Additional Auxiliary battle maps, helpful in-game support items, and more will be released by Oct. 31.
I'm sure this means exp-boosting maps (all the 3DS games have this kind of shit), gold-farming maps.... The support items sound like support-boosting presents or blacksmith materials, maybe even food, seals.... "And more" I wonder what can be, maybe some new activity for the monastery, like a new way to teach non-weapon skills to Byleth. Maybe petting dogs/cats give you charm.
Wave 3: Additional quests and costumes, plus a free update, will be released by Dec. 31.
Additional quests sounds like monastery quests, so it sounds like more ways to obtain reputation. I wonder about costumes, as the game has a ton of characters I don't think we will get specific costumes, more likely it will be generic costumes for all the characters. The free update will be Lunatic I think.
Wave 4: New story content, with additional playable characters, locations and more, plus a free update, will be released by April 30, 2020.
New story can be either a prequel (there's enough lore) or an alternate, shorter route. As the game has a rich lore, I don't think this will be characters from other Fire Emblem games like what they did with some 3DS FE DLCs. The new locations detail makes me thing tha the new campaign will have a new explorable area, as new maps should be the minimun they create (it's a 25 € season pass and the previous content doesn't seem that relevant). The free update seems to be the Infernal mode.
Overall, I don't think that more exp, items, gold or renown is needed, as the game is fairly easy even in hard and the harder modes will come later, so I'm not that hyped about "helpful" content. Costumes and quests are nice, but I hope they focus all the effort in a good, meaning campaign that has lots of new content, I think that the game re-uses maps enough during the existing routes.
