I'd rather keep 48*x. 44.1 doesn't divide from standard time bases, higher multiples less so. It was born of a terrible compromise between fatuous Beethoven and an easy to use form factor. Also, production routinely occurs at 48*x, usually 96 or 192. The downmix to 44.1*x will introduce artifacts that didn't need to be introduced.>>5791
If some teen can hear in that range well, I say more power to them.