Yeah, I was thinking about that too; unsure how Boundless’ economy would react! I’m more of an armchair economist, so most of what I say is probably wrong 
It would certainly be a lot of fun to have some items that become more scarce over time - all the collectors would love it; though it can be pretty frustrating for newbies that missed the gold rush…
It’s also kinda interesting how it was portrayed in that article: Even though most mined blocks are non-renewable in MC, the size of the worlds (even when constrained) means that the supply of them is effectively infinite. The amount of player effort to mine a diamond seemed to be pretty stable (otherwise the price of diamonds would have invariably gone up). It might be better to frame it in terms of that (player effort)?
Re: the current economy, @OmniUno put up a really thoughtful list of suggestions for it that you might want to dig into, too: