The Doctor is discussing how his current situation--a population hiding from an alien attack--reminds him of several similar situations:
"The Daleks' destruction of the Atreides' systems?"
So the Daleks destroyed Dune?!?!?
Perhaps Davros needed some spice for his experiments?
Davros, Emperor Of Doom?
Daleks vs. Sandworms?
Or is Paul able to convert a sizable portion of Davros' troops to his side, so we have a scene with thousands of Daleks chanting, "MUAD-DIB! MUAD-DIB!!"
And maybe, just maybe, we can see the Doctor fight this guy:
From Doctor Who: The Twelfth Doctor #13 (2015)