There's no need to wait for full publication of Metro plans to find out what will happen. It's already been decided.
https://www.transportxtra.com/location/wales/ has a few good articles by Rhodri Clark on the 'Metro'. It's a paywall site with a free 2 week trial available.
An article about TfW taking over operation of the new bus station from Cardiff Council ends with this paragraph:
"A significant change is expected within Cardiff Central railway station with the planned conversion of the Core Valley Lines to light rail. Long-standing through services from the Valleys to Barry and Penarth would turn back at Cardiff Central. Also proposed is a light rail spur from the existing branch line between Cardiff Queen Street and Cardiff Bay. The spur would terminate in Cardiff Central or south of the station, providing a direct rail connection from Central to the Bay."
Which is
exactly what Cardiff Bus' Baycar bus does already! Trams will be following an
identical route and will not be any quicker. But what minister wants, minister gets.
Also, confirming what myself and other posters have been saying for months:
"Other sections of the Valley Lines, notably from Cardiff Central to Maesteg, Ebbw Vale and Bridgend via Barry will remain diesel-operated for the foreseeable future."
Another article suggests that TfW think they can light rail electrify the sacred Core Valley lines for £400 million with battery - electric trams. The 'surplus' of the £734m left from the allocated VL electrification funding pot would be used to build on-street running tram lines in central Cardiff and the 'bullett train to the Bay' (specifically to the Assembly) that Plaid Cymru have raised issue with, rather than electrifying to Barry and Penarth to enable cross-city tram-trains to run.
And the Assembly and WAG suits will still use their cars.
https://www.transportxtra.com/publi...or-wales-to-operate-cardiff-s-new-bus-station
https://www.transportxtra.com/publi...s-valley-lines-wiring-will-come-in-under-500m