A few days ago he posted (then I think deleted) this, which among other things makes me extremely inclined to not believe anything he says:

In March 2019 I teased the Pixelfed mobile app. The only problem was, I didn’t know how to write one. So just like the original “federated instagram” post, I faked a commercial to build hype. It was coming along well. Then in mid 2020, I came out and put the app aside. It wasn’t until late 2022 that I found a Pixelfed react native app, and cloned it and tinkered. In 2023 I released the first Pixelfed app, but it was slow. I rewrote it from scratch in May 2024. From faking, to making!