FiA stipulates there must be only TWO exhaust outlets from the engine. What McLaren is trying to do is to work around this rule by having two exhaust outlets, which will become the inlet of that box, which then will have several exhaust outlets to blow the diffuser. They could be legal if that ceramic box is not considered to be included in the exhaust system.
Scarbs:
I think the definition of exhaust outlets is the key thing here. If McLaren term the exhaust as the "tubular" metal exhaust pipes, then the chamber as "bodywork" because its constructed from different material (Pyrosic - a Glass Ceramic Composite). Then the chamber can have multiple outlets, as long as it only has two inlets
great work Phil
