dont know if true... but woudln't rule it out. they had a billion dollar machine with the beatles. It was the 1960s. With money, one could replace and nobody would notice. Back then, quite a few people noticed... but without the internet, it just went away with time.
if i'm in a band and we're the top band in the world, and a member dies, and we have opportunity to quietly replace him and make hundreds of millions... it's a no-brainer, really.
they changed out the main guy on the Wiggles, and most kids didn't even notice. But I did.