The silence is deafening from HB they must know who owns the copyright of the sounds or for that matter of everything to do with the game, it's pretty petty minded from companies anyway contacting a small video producer, as you said you don't charge money for your videos so just add a few lines of text similar to this.
"Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for "fair use" for purposes such as criticism, comment, news reporting, teaching, scholarship, and research. and see what happens.
This is why companies get bad names chasing the little guy, it's the same with the music industry if I buy a record I should be able to do with it as I please within reason, but oh! No you can't copy it there you can't take it there, and yet they change the technology every five minutes making you buy multiple versions of the same damn thing and that's ok. Keep up the good work Jim.