[swang]

i think you're extrapolating a bit too much from that tweet from more than 3 years ago considering they resumed buying them ~6 months later.

https://twitter.com/Zerodium/status/1326498688621948928

now did they have too many? maybe. but maybe also because they were expecting apple to announce a new ios at the wwdc that was happening in june.. or maybe lots of 0-day exploiters suddenly wanted to dump their exploits knowing that apple was probably going to be patching them soon. oddly enough that tweet about resuming payment coincided with the release timeline of ios 14.

most of this is irrelevant though because we lack any information. what is, "too many"? 10? 100? 1000? it could be that just like any other middleman they sometimes need to sit on "inventory" and they can't just buy up that many at one time in case apple fixes them all in an update.