i interpreted it as a recap movie with exclusive scenes but still hype!
official announcement tweet (seen below)

So is this going to be a partial sequel? I wish we would just get a 3rd season as there is more than enough material.
chapter 153, right? It stopped in chapter 113 in 2nd season... I think they need like 60 chapters, right? Still around 20 are needed thought.
And they drop every 2 weeks, so that's 40 weeks, almost a year, plus let's say 6 months of anime production, season 3 can't drop until Winter Season 2026 at the earliest. Honestly, though, I'd prefer they do that instead of cramming a recap + 30 or so chapters in a movie. And let's say a few OVAs here and there to keep the engagement
there isn't enough manga material for a new season, so this is hopefully just something to tide people over and buy time before they announce and make a third season
edit: WE STAY WINNING
https://www.reddit.com/r/anime/comments/1rtf7qo/the_dangers_in_my_heart_season_3_announced/
there is enough material for a movie for sure, so i don't understand the meaning behind making a recap movie, there is 40 chapter left to adapt as of now . you need 55-60 chapter for a full season. they could have made movie with new content rather than recap . it's bound to flop ( movie )
Yeah but this isn't a shounen where you can just make any of the lead ups to a fight and the fight a movie, and there isn't really a part in the manga currently that has "movie" worthy moments. Recap movies are a normal thing in the industry and i doubt it will flop, especially with how popular the series is.
We get new manga stuff skipped added, and you get a succinct recap of the 2 seasons. I see it as a win either way.