It's more than that. Before the sale of the Fallout IP, Interplay were all but dead in the water. This looks effectively to be the death-knell.
Also, technically Black Isle, Interplay's internal developer, put together the first two Fallouts and Tactics (?). They're also renowned for, among other works, the RPG Planescape Torment
which you may have heard a few people praising to high heaven around these parts.