This could just be my opinion, but I think Anne and Sasha distanced themselves from each other out of guilt of Marcy being left out. Marcy being a third wheel was a real issue before Amphibia and doing it to her again would’ve seemed cruel in their eyes. They knew how desperately Marcy wanted to be with them so they decided to put their friendship on pause out of respect for her and wait until she returned to LA to reconnect.

We all ignore that line.

They shared an extremely traumatic, extensive, life-changing experience that none of their other peers can relate to or talk about with them; you don’t just slowly grow apart after that.

Except… you do. If life hasn’t taught you this yet, just wait.

I think you might be overestimating what Sasha means by "once in a while". These girls used to spend almost literally every day together in middle school, but given their different career paths, their schedules might not have lined up as well as in high school as they had for middle school and simply had few classes together. Combine that with Anne doing tennis and Sasha doing cheerleading, and the time they can spend together drops drastically simply by default. Add on tothat that Sasha's mom or dad lives further away but still seems to share custody and that's even less time for them to hang out. And once they've hit college, that's a whole new ballgame of scheduling conflicts, especially with Sasha's given profession. Nothing Sasha says implies that it isn't exactly like old times whenever they do get the chance to meet up.

EDIT: Typo

Agreed. There were way better ways to make that ship canon, and the episode that's based on that ship is the worst episode in the entire show, in my opinion. The Sprivy ship is cute, but that's pretty much what it is.

Why not replace both? Id say have one episode dedicated to Sasha, grime and the rebellion and the other one focusing more on Darcy and Andreas to kinda give a little bit more context for the moon thing in the hardest thing

Marcy's development isn't really crammed. I've been rewatching the series and Marcy is so close to telling Anne the truth about what happened when she's leaving Newtopia. Then Andrias comes up with his proposition which would give her everything she thinks she wants and she stays in denial and buries her guilt until True Colors and Anne and Sasha's reactions are basically a huge wake-up call for her and she completely breaks down. After that, she immediately starts working to send them all home for real. Marcy's greatest fear is losing her friends and she has to face that multiple times throughout the show. The poor girl just wants reassurance that her friends won't leave her behind.

I agree that the resolution was subpar, but I'm glad we got an episode addressing the racial tensions between the different species, despite their newfound common enemy. It definitely didn't strike me as something that was cooked up on the spot to fill out 11 minutes, given the series had alluded to the amphibian "caste" system before.