Well, if they’re doing what many other places are doing, which is implementing with a focus on mastodon, then you won’t be able to. Same thing happened with the Wordpress plugin recently, AFAIK.
The issue is that mastodon does users and lemmy does groups (ie communities). From that I could tell, the wordpress plugin for ActivityPub implemented their federation as a user. This way, it’ll work more or less “naturally” on mastodon. Already you can see an issue with this IMO, as any given blog is not necessarily a single user: often a blog hosts content from multiple users, in which case federating as a group could make more sense.
My bet is that flipboard are doing the same, even though it makes even less sense for a news aggregator to not have an ActivityPub feed that is organised around a group. Of course I could be completely wrong about this. But the force to optimise for mastodon, which doesn’t do groups well at all, is very real and so I’d be willing to bet I’m right.
Either way, the point still stands that mastodon’s size is distorting what the fediverse looks like toward its idiosyncrasies. Which makes a lot of sense for those looking to plug in to the fediverse such as flipboard, but by the same token raises rather significant concerns about the quality and propriety of mastodon’s stewardship and influence over the fediverse.
Beyond all of that though is the question for lemmy and users here as to whether they’d be interested in being able to follow users more or less like a microblog? Kbin is trying something along those lines. Facebook (and friendica on the fediverse) have had a mix of user and group driven structures for a long time now.
My personal take is that lemmy’s general reddit-like design could create a rather interesting platform if it were to allow user’s to create their own personal “communities” which could be subscribed to like any other. The idea being to not lean into the microblogging idea (where the character limit here is something like 50,000 anyway, so “micro” is inapplicable) but instead to lean into the idea of a blogosphere in which people’s personal communities would become places for posting longer form content with the purpose of starting conversations.