Moneyness: is just an academic term for how money-like a certain thing is. It's precisely what you're describing: how close to being capable of money services is gold? ISAs? Stocks? Treasury bills? If you're a big bank, you can repo Treasury bills; if you're Apple you can pay with newly printed Apple stocks. Some retail brokerage accounts lets you visa-debit card swipe from your index fund holdings.

It's essentially a measure of liquidity and usage, and it's veeeery arbitrary.

I can't account for the shift, either. My best guess is that it's a bureaucratic-statistical decision and it was time. The timing -- mid-pandemic -- was of course awful and has confused looots of people.