Yup. There’s a few old re-releases there, not sure if they’re patched up for modern Windows though. Actually, they had a publisher sale on Steam quite recently.
And not just that, when they acquired LucasFilm they not only got a backlog of old Star Wars and Indiana Jones games already on Steam, but also Sam & Max Hit the Road. AFAIK Sam & Max is an independent franchise but LucasArts and thus Disney own the rights to Hit the Road.