Sometimes the same idea is so big that it gets used again and again from different perspectives like Voyager's holodeck stories etc. but if GR wrote The Robot's Return before Lucas wrote The Changeling then who is stealing from who? All Good Things to me was not a homage but a rip off. that's it. If Vonnegut was still alive he probably wrote have sued for it's similarity to Slaughter House Five and would have been justified. Unconscious stealing from some memo is still stealing evidenced by RDM's Tapestry.