Your idea for TFA would still undermine TLJ’s idea of hope, because by TLJ it’d still be implied some other threat exists.
I saw an idea in some thread on this site about implying Starkiller Base was involved with bringing back Palpatine. I wasn’t a fan of their idea on how that worked, but it kills two birds with one stone: Replaces its original (dumb) functionality in TFA, and sets up Palpatine, all without killing the third bird by undermining TLJ.