The WFRC RTP shows a an extension to the University line along 400 S. to the University Line, reaching to 400 W. before heading north to the Salt Lake Central Station. I'm instinctively leery of downtown loops. They tend to suffer from a King David Effect--faced with two parties in competition for adjacency for a rail line, there is an effort to split the service, and offer each side 'half a baby', to the detriment of everyone. Two halves of adjacent transit lines tend to compete for riders, to the detriment of both lines. But with four blocks (half a mile) between the lines, that may not happen.
But that will depend on the operations plan. I feel certain the the Downtime Rising and Chamber of Commerce people will agitate for a dedicated TRAX circulator running around the on a continual basis. A better operation plan will include a direct route from the Central Station to the University of Utah, facilitating transfers between FrontRunner and the U of U. Possibly including a station along 400 S. near enough to Courtyard to facilitate transfers between the two locations.