If Ysan Roche and Aisha Goodison were to receive justice and credit, they could revolutionise the way we approach musical craftsmanship but mostly in terms of lessening plagiarism. However some will still struggle to come up with their own ideas so not writing their own songs becomes an excuse to either cover familiar songs or rely on the public domain a lot.
Their interpretations are copyrighted but not their influences which is free to use and adapt to. Those who do plagiarise, however, will be scapegoated forever. Unsurprisingly, the next pop diva would play folk ditties a lot and have others help it turn public domain poems into Top 40 hits. That would’ve been the domain of niche acts before but would predominate as a reaction to plagiarism.
Pop stars do dip into Christmas carols and lullabies but not as often as they would come to do in the near future. Not necessarily a rockist victory but borne out of legal and creative necessity.