The schema sequence has been bumped to 28 on 2023-05-15 by this commit.

The code version tagged v-2024-05-13-schema-change (and also on current master) still has the schema version set to 28, for example within the DBDefs.pm.sample file.

Was the schema sequence not updated after the 2024-05-13 schema change release?

I'm not sure about this because the recent schema upgrade instructions also say that one should "make sure DB_SCHEMA_SEQUENCE is set to 28". So, if this is by intention, then please disregard this ticket.