Distributing HEVC content is royalty-free, even commercially[1] - however, royalties come into play with distributing encoders and decoders, and it's the latter that could cause problems (similar to the case of Firefox and H.264 decoding support).

[1] http://www.mpegla.com/main/programs/HEVC/Documents/HEVCweb.p... - page 7, HEVC License Terms