Not likely enough, though.
I've watched Mastodon and its users for years now. From my experience, for more than 50% of all Mastodon users, the Fediverse equals Mastodon. That doesn't mean that they don't count Lemmy as part of the Fediverse. It rather means that they've literally never even heard about Lemmy. They haven't heard of any Fediverse software other than Mastodon.
There are lots of ATmosphere users who haven't even heard of Mastodon, much less the Fediverse.
Another example: I'm an active user of a virtual world system named OpenSimulator. It's extremely similar to Second Life, also because it uses the same viewers. It's free-as-in-license as well as free-as-in-free-beer and free-as-in-most-grids-don't-even-have-in-world-payment. It's open-source. It's decentralised to the point where your avatar can teleport to other grids (= worlds = server instances). And yet, the vast majority of OpenSim users have never heard of Mastodon either, much less the Fediverse.