I need to see Doom (eternal) benchmarks before making any guess. If it can perform well in that respect it could be a competitor going forward, but the driver morass of D3D will take a lot of work and I doubt they will have done so in the short term.
They've added under markets "desktop" now on their homepage: https://www.imaginationtech.com/markets/desktop/
There's no mention so far for D3D in the software support relevant paragraph.