Related question; does second edition Prosperity still have mats? I don't see any mention of it on the Wiki. Empires does not have mats; right? Which would imply that Donald decided that VP tokens don't need mats; and thus why bother having mats in second edition Prosperity?
Actually it was an important rules change that Empires
didn't have mats. Or to put it more accurately, it was an important rules change that VP tokens are not put on a mat. Instead, you
take VP tokens (and then might put them optionally on something like for instance a VP token mat). That rules change mattered for the version of Possession introduced in Empires.
But then Possession was changed again, so it doesn't matter anymore.
But Prosperity was released in the meantime. I checked now, and yes Prosperity 2E does come with the 8 mats. But the rules for the mats are changed.
Prosperity 1E:This expansion comes with 8 player mats and VP tokens for use with the Bishop, Goons, and Monument Kingdom cards. [...] A player takes a mat of his choice as soon as he needs one.
"+X VP" - The player takes X VP tokens. [...] When a player first takes VP tokens, he takes a player mat to put them on. Prosperity 2E:Prosperity has player mats for tracking VP tokens. You do not have to use one; if you do, take one when you first have VP tokens.
Cards say "+1 VP" (or other amounts) to indicate that a player takes VP tokens.