TLAPD

is there anything else going on in this event (like any seasonal maps) or is the new kaijuwar the only thing?

It's split in 2 events.
One is the war itself. The other is the Boss Battle which is coming next week.

I think he was asking about returning Seasonal maps.
Here's the lot of them:

NON SEASONAL TLAPD MAPS:
/join piratewar
/join hiddendepths
/join tlapd

SEASONAL TLAPD MAPS:
/join blazebeard
/join manacannon
/join midnightwar
/join midnightcrown