I think the Bitcoin ETF and Bitcoin Future are no different, both of them are the vehicles of the popes to deceive/manipulate bitcoin prices as happened in the middle of December 2017.
I can very well imagine that an approved ETF would arouse some peoples curiosity, which then could lead to a rising interest again.
But that only applies temporarily and then most of the bitcoin users will probably be overshadowed by the dark growth of bitcoin as it's now happening, bitcoin's difficult to rise.