The mezzo-soprano becomes the contralto

[secret love]

Let's reflect on this:

Until 1998, according to the almighty Google, Stevie Nicks was a mezzo-soprano singer. From 1998 to now, she has lowered her range to a contralto, the lowest of all female voices, of a similar pitch to the likes of Cher.

Christine is... an alto? I think she is, anyway. Which would mean Stevie used to sing higher on harmonies than Christine did on lead, on songs like Over My Head, although I can't find a YouTube video to demonstrate this - help please.

But here are two videos to demonstrate the dramatic shift in pitch of her still beautiful voice:








My own range is F2 - F4.
It is an unpopular opinion, but I prefer the current "contralto" voice to the "mezzo-soprano". What do you guys prefer?