Trademarks and copyrights are different. Trademarks have to be actively used and/or renewed, or someone else can use the mark (usually a name or logo). Copyrights last a long time without need for attention.
Long story short, Hasbro can use RiD concepts, since any relevant trademarks either expired, or are Hasbro's to start with. But they don't own the actual RiD series itself. THAT is protected by Copyright that Disney is believed to still own, whether Disney does anything with it or not. This means we're not going to be able to see an official release of the series on DVD, BluRay, streaming, whatever anytime soon.