Web Part Custom Message

Good Day:

Currently there are some small Yammer experiments going on where a small number of employees have access to it.  A recent Communications Site was set up that everyone in the company has access to. The Communication Site owners added a Yammer Highlights web part.  Now, since anyone in the company has access to the SharePoint Online site they see the Yammer Web Part and get a message/link to Join Yammer which takes users to a URL that is not usable at this point (not all associates are set up and adding new users to Yammer is restricted for now).  The Business was asking if there was something we could do from a SharePoint web part perspective to allow in having some sort of custom message showing up to those users not yet set up for Yammer.  I find this highly unlikely since the web part is working as designed but i still wanted to ask for feedback. Thanks