The approval document (here) lists 30 two-car and 12 three-car units. The annex describes them as two-car non-ETCS units 197001,002,004-021,042-051 and three-car non-first class 197101-112.
197003 (omitted from the approval) was previously said to be an ERTMS/ETCS unit for testing purposes. I presume that the range 022-040 is earmarked for Cambrian ETCS units?
Interesting tidbits:
Maximum speed is 160kph/100mph, or 105kph/65mph is suspension is deflated.
Operation in service permitted as three coupled sets up to 9 vehicles, or 4 sets up to 12 vehicles in ECS/rescue scenarios.
Tweet says 20x two-car units authorised, but approval document says 30 two-car units. Regarding ETCS, this appears to be confirmation that 21 units would be fitted, but having 197003 out on its own rather than having a distinct subclass looks decidedly odd.