Hendrix may be disappearing from POP culture, but his fans know where to find new music and videos- unfortunately, his sister is a bit of a money grubber. People make videos about him frequently, including some showing why it's so hard to sound very similar to him- it wasn't just his playing a right-handed guitar as a lefty, but the studio that was built for him, Eddie Kramer's recording techniques, the new effect pedals that he used (some were made specifically for him) and the fact that he was never afraid to ask "What will happen if....?". He also recorded almost constantly when he was in the studio- that led to a lot of songs that were assembled and a constant array of new licks and riffs. People hear new music now and it's mostly rehashed, but in some cases, it's rehashed obscure music- that's why it seems new and fresh.
WRT Queen's music that's replayed and used for commercial applications- dig into their catalog and it's only a few of their well-known songs that are used, but they had some great stuff that would probably never be used because it's too foreign to mainstream pop-based listeners. Most people know 'We Will Rock You', 'Bohemian Rhapsody' and a couple of others, but that's all. I'm not sure that makes them more 'relevant'- it just means those songs are usable for commercials and TV/movies.