Yes, older boosts are the only thing paying out these days at a rate similar to 2024 (and in fact matching 2023, I would say).

The boost multiplier seems to have been retained - though I would say it's always been excessive - and older stories of all kinds inevitably benefit from the 'new-to-you reader' factor, as they have just popped up in a random user's feed, so not a follower or a recent reader of your articles.

It's an odd, you might say downright perverse, approach. Whatever logic they think they are following, I'm pretty sure there will be several flaws in there they haven't spotted, because that's always the case with Medium.

And I presume (though am not certain) that 'Let's see how we can piss off as many regular, quality writers as possible, drive them from the platform, and just leave the 'what I had for breakfast' bloggers and bots here churning out crap' wasn't in the brief...