@Ring Team
You’d only ever establish how a character died, and how other characters reacted, if that information was relevant to the plot.
For example, in Finding Nemo, you’d show that Coral and the eggs were eaten by a barracuda to establish that the ocean is a dangerous, unforgiving place, and how Marlin became an over-protective parent.
In Frozen, you’d include a scene of the sisters attending a funeral because it helps inform where they’re at emotionally when the story starts. Without parents to guide her development, Elsa is stuck in her “conceal, don’t feel” phase, and Anna is completely starved for a human connection.
If they showed Argyle’s death, you’d lose the match cut from filly Sunny going to sleep and adult Sunny waking up. The scene of her waking up and getting ready is bright and upbeat. Sunny walks right past Argyle’s shrine smiling, but the camera stops and holds on it for a few seconds and the music slows. Next time we see Sunny, she’s still smiling. This tells us that whatever happened, it’s not something she dwells on.