Replied to Social Menu & Social Media Icons: Add Mastodon Support · Issue #10338 · Automattic/jetpack by transmothra (GitHub)

Please add support for Mastodon, a distributed, decentralized, federated micro-blogging platform popular among people abandoning Twitter and Free software/Free culture enthusiasts (many nodes exist)

I’ve noticed that @janboddez has a plugin that will do this for a variety of Fediverse instances including Mastodon:

There’s also an approved version in the repository named Add Fediverse Icons to Jetpack