Over the last 3 weeks of our data (June 21 to July 12, 2023), we saw a weekday daily tweet count drop from the 1,272 pre-Elon average to just 333 tweets a day, which is about a 74% drop in weekday tweets. The 2-week rolling average (including weekends) dropped down to 272 tweets over the final 2 weeks. When I attempt to remove automated CVE announcements (bots), the drop is even more significant, dropping from over 500 a day down to 66 over the last two weeks, an 87% decrease in CVE-related tweets.
Relevant HN Discussion: https://news.ycombinator.com/item?id=36780739
From the discussion it seems most of the infosec people have moved over to Mastodon already which is nice.