Dolby’s audio formats (DTS, Atmos, etc) could be streamed with “pass-through” (bitstream) to an av processor, as with every media player on the market.
Audio files from DVD audio, or even blue ray audio, are stored in our hard disk database, usually as flac with Dolby encoding, and roon is not capable of streaming them.
A cheap blue ray player, like sony 700/800, is capable of playing all these files, and this is not possible with roon.
Dolby Atmos streaming is on the way (tidal and others will follow) and there is no need for decoding, we all have a compatible av processor, bitstream with pass-through is what we need.
Maybe even streaming of movies (blue ray) is a good idea.