I was going to say the same thing as other commentors- the Beatles were quite open in admitting they were influenced by rockabilly and early rock music often originated with black artists.

John Lennon also pressed the rest of the band to bring in Billy Preston full time as a Beatle- he was with them so much he was called "the fifth Beatle"

What made the Beatles (especially the songwriting team of Lennon & McCartney) was their ability to absorb and yes even imitate at times.

John Lennon once said that their "Long Winding Road" was Paul's work to imitate Simon & Garfunkle's "Bridge Over Troubled Waters"

Ultimately while influenced by American Black artists they didn't do all that much "rockabilly" or even covers except in the first 3-4 albums