Do seem to belatedly decided not having toilets on tram trains or stations was not practical.
Although the limited number of nine extra locations won't all be ready in time which suggests it was an afterthought.
Transport for Wales (TfW) is entering the final stages of preparation ahead of the introduction of its first brand‑new tram‑trains on Pontypridd to Cardiff Bay services this summer.
news.tfw.wales
The full list of toilets is on this link :
Cardiff Central platforms 1 to 8 (will 398s use any other platforms ?)
Cardiff Queen Street platform 4
Pontypridd, Trefforest (temporary whilst refurbishing)
Radyr (temporary in car park from 22 June)
Abercynon, Aberdare, Cwmbach, Llwynypia, Merthyr Tydfil, Merthyr Vale, Penrhiwceiber, Tonypandy, Treorchy, (being added)
Also Porth bus Interchange
Transport for Wales | Buy Cheap Train Tickets and Check Train Times
tfw.wales
Don't know how each has progressed, but hopefully someone local can update status of each of the 14 locations