If I remember correctly, he noticed that his account with 100,000,000 plus followers was only getting 40,000 or so views. This lead to a Twitter engineer saying maybe his content wasn't interesting enough to get views and getting fired. And later on Musk said that they found a bug in the fanout system because his account was so big it basically broke things and they fixed it.
I remember everyone agreeing with the Twitter engineer who said maybe his content wasn't interesting enough, while to me that seemed odd. If people follow an account and they tweet and they're online they should have a high chance of seeing that tweet. That's the entire point of following someone. If someone I've followed tweets something I would like to see it.
The fanout bug was in weighting how blocks affect visibility and fanout.
Apparently it was an absolute and not a relative thing, so the huge amount of blocks musk has affected their visibility.
You don't, at least for me, I have 5700 followers and most posts (with art) only see 200-500 impressions, whereas a year ago I was getting 3000 on average. The Following tab is clearly (at least for me) not in timeline order, so most of my followers never even know I posted anything. Since I post art most of my followers are artists, so you would think they would see them. Impressions (which are Twitter putting tweets in a timeline so that people scroll by them) are not under the control of the poster. Likes per impression for me are up, so interaction is higher which is supposed to increase how often tweets are shown, but only timely retweets seem to help any.
I am trying to figure out how the algorithm decides on what to show in the Following tab, but the code is way too big to analyze without being able to run it and look at logging/metrics/stats.
I remember everyone agreeing with the Twitter engineer who said maybe his content wasn't interesting enough, while to me that seemed odd. If people follow an account and they tweet and they're online they should have a high chance of seeing that tweet. That's the entire point of following someone. If someone I've followed tweets something I would like to see it.