Beacon and Site Builder have separate functions. The focus on the SiteWorks project is to migrate SiteBuilder sites to WordPress with the features available matching SiteBuilder as closely as possible and to enable automated content migration. u3as will need to continue to maintain some groups related information in Beacon and some in SiteWorks, just as they currently do with Site Builder. 

While nothing official has been decided there is demand and a desire for integration with Beacon. A small team of volunteers has been formed and will work towards making a proposal to the Trust.