The common translation for bismillah is “In the name of Allah”
Interesting, no?
The composer, Freddy Mercury, was raised in the Zoroastrian religion, an ancient Iranian multi-theistic religion which pre-dated Islam. The word floated downstream into Islam, apparently; but certainly Mercury's life was anything but muslim or even religious. His parents buried him in a Zoroastrian ceremony; so I wouldn't think the word indicated anything from him other than a long-held cultural artifact he remembered from childhood.