Another thing in the same vein that I cannot prove, so this is just a theory with no confirmation that I'm aware of:
Back when season 1 was coming to an end, the titles for season 2 were released. They had a wikipedia page, the first handful had plot summaries, the end of the list had a lot of Title TBC, but there was a list of all the episode slots.
Which would put the Season 2 episode count similar to the 53 episode long Season 1.
And then the final of season 1 aired.
And the show's explicit lesbian-ness was made, um, explicit.
And suddenly those 50 titles were split into Season 2 and Season 3.
This wikipedia page says of this:
"Season 2 and Season 3 were produced as one season of 26 half-hours, comprising 49 regular episodes, 1 double-length special, and 6 shorts. When the season was officially split in two after the fact, 26 of the regular episodes and the shorts were aired as "Season 2".
and then further down the page:
"Season 3 consists of the remaining 23 regular episodes and 1 double-sized episode produced alongside season 2."
A similar thing seems to have happened with seasons 4 and 5.
Now, I can't help but wonder if there was a contractual obligation to let Steven Universe have a certain number of seasons. Before the Suits realised the show was gay. And then suddenly the seasons were halved so they could reach the contractually obliged number waaay quicker.
Because splitting season 2 in half doesn't feel like an artistic decision. The viewer can feel the cut; seasons 2 and 3 both feel the absence of each other. They're one season.
Now, it could have been a money decision. Suits love money. Maybe the split allowed the accountants to do some obscure tax thing or something.
But the timing of the split announcement feels telling.
I think Steven Universe started having its plans cut to pieces as early as the end of season 1. If not sooner. Because of the gay.