either the pilot for the next season or inconsequential to the larger plot.
Almost certainly the latter.
From Wikipedia:
A compilation film of the first season and an original episode, "Hoshina's Day Off" (保科の休日, Hoshina no Kyūjitsu), was screened together in Japanese theaters for three weeks starting on March 28, 2025.
It's going to be filler, possibly even comedy, based on the name.
Almost certainly the latter.
From Wikipedia:
It's going to be filler, possibly even comedy, based on the name.