Meta blocking Pixelfed links is not shocking to me.
They’ve been downright dirty towards Pixelfed for years. So much that @dansup@pixelfed.social has mentioned their shenanigans multiple times. In fact, I remember him talking about similar circumstances all the way back in 2021.
https://www.404media.co/meta-is-blocking-links-to-decentralized-instagram-competitor-pixelfed/