That metamaterial is, AFAIK, some sort of semisolid repetitive mesh (I mean solid and air or solid and liquid). So you’d be blocking things almost fully.
Could it be used to tune an exhaust to benefit a turbocharger?
Sure, why not?
Sound is an aural artefact of energy transmission, & one of the 'unforseen consequences' of the very efficient current F1 turbo-compound ICE units has been a tangible loss of that 'visceral thrill' sound factor
due to high-energy exhaust ejecta, so perhaps some 'tweaking', ah, I mean 'super-computation' of the
functions of the device you posted could be utilized - instead of the crude 'vuvuzela' approach - used now?
"Well, we knocked the bastard off!"
Ed Hilary on being 1st to top Mt Everest,
(& 1st to do a surface traverse across Antarctica,
in good Kiwi style - riding a Massey Ferguson farm
tractor - with a few extemporised mod's to hack the task).