As above, no it does not have to be KMC, only the the right type/spec.
Usually the cheaper chains are the strongest and the more expensive/lighter the chains become, the weaker they get regardless of what gibberish the marketing bods spew. I'd say just get something like a £20ish Shimano, SRAM, Wipperman. KMC chain.
(I just bought a replacement KMC (EL 11 speed) 2 weeks ago for £65...... looks very fragile. So little faith I have in its 'strength', today I ordered a Wipperman chain.)