@J12t they can

* participate in the community such as promoting diversity in their workforce
* post updates for opt-in followers
* interact with upstream and downstream projects, e.g. a company that uses Krita for artwork
* promote Pepper and Carrot because they all should :)

I follow several companies in the Fediverse ( mostly FLOSS projects )

if people will install a fast food chain's app on their phone they'll probably also follow them on social media