^Actually it does not appear that this junction will be a true wye. Trains
will not be able to follow the old Gold Line route.
https://www.apta.com/wp-content/uplo...on_Ian-Ong.pdf
Also, I am less concerned about the operations problems after viewing these illustrations. An outbound train going to Pasadena will simply sit at the station platform and wait for an inbound train from East LA rather than creep out into the tunnel and then sit there while the riders get impatient.
That said, the Regional Connector will put a lot of pressure on Metro to improve the interlined trackage and wye near the Staples Center. It'll be tough to move all of that underground where it is presently located without a lengthy closure of that section of the line and a bus bridge.