Very much agreed.
Unlike Gotham By Gaslight, Red Son, or DKR, Death and Return of Superman is not self contained if adapted verbatim. There are plot threads for major characters that require quite a bit of back story if you were to do them straight up (Matrix, Lex 2, Eradicator, and Cyborg Superman). Regardless, for the format of 2 animated movie that are both a little over an hour, you gotta do some considerable fudging of the details even if you're going stand alone continuity.
They finally get a movie for this version of Superman, have the opportunity to reformat him as the please without calling it a reboot or making it confusing, and they get to cash in on Death of Superman.
I mean, the only point of comparison that I can find in this already established universe is with Batman. They adapted Grant Morrison's "Batman and Son" arc, and they used it as a way to give Batman his first movie away from the Justice League in this continuity. Even though they remained pretty faithful in some areas, they took liberties in others. It ranged from small things like Dick taking on parts of Tim's role up to adding in Deathstroke. And in Deathstroke's case they were setting him up for the Teen Titans: The Judas Contract movie adaptation, another partly faithful and partly working with what they have and what they want moving forward.
I expect the very same of this film.