Or alternatively they "redeemed" a bunch of unbacked tokens that they (or a partner company) owned, in order to give the impression that their redemption window

Or alternatively they "redeemed" a bunch of unbacked tokens that they (or a partner company) owned, in order to give the impression that their redemption window was processing large amounts successfully. I'm sure that's not actually the case, but it would be consistent with the "Tether printing unbacked tokens for its own trading" theory of Tether fraud. This may seem like a conspiracy theory, but: the reason these "conspiracy theories" are so easy to believe is that Tether is unregulated and highly non-transparent.