Do they have researchers working on new audio and video formats?
Or is it now all just a self-perpetuating machine for generating licensing revenue, based on existing patents?
Sorry for the ignorant question but I'm clueless about their ongoing contributions to the industry.
So they do actually contribute some worthwhile stuff. And some of it is open standards (like PQ & ICtCp).
They also absolutely troll licenses though. Dolby Vision being a perfect example, check out the "profiles" section of https://en.wikipedia.org/wiki/Dolby_Vision and you'll see some truly dumb Dolby Vision profiles that exist obviously just to slap a Dolby Vision license & branding on an otherwise boring, generic video format. Dolby Vision 9 is a perfect example, it's not even HDR at all. It's literally the same stuff we've all been watching for a decade+, but with marketing wank shoved onto it.
Short answer is yes. Search for "Dolby" under "Author Affiliation" in the AES paper search [0] and you can see the research they publish. (the papers themselves are unfortunately behind the AES paywall, but if usually authors will send you the paper if you ask nicely).