Based on my experience with similar things (e.g., asking my LS members to check our guild site), I think the perceived "hassle" outweighs the need for recruitment. In a new and thriving community such as Mateus, there may be no real need for extra advertisement. If the community feels that Discord-only suits all of their needs, it'd be a difficult sell to get someone to place additional work onto themselves, however large or small.
This is just my idle speculation, though!
This is just my idle speculation, though!