Intel Xe And Arc Graphics Lack DX9 Support Forcing DX12 Emulation
Clearly, it's complete and performant enough for Intel to rely on it entirely for DirectX 9 applications running on its graphics adapters. This information comes directly from Intel itself, by the way. The blue team published a support article titled "Which Intel Graphics Products Support DirectX 9 (DX9)?" You can see a screenshot of the whole article above.
The comical part of the support announcement is how Intel rather unashamedly passes the buck for any issues in DX9 games to Microsoft. The article clearly says "troubleshooting of DX9 apps and games issues require promoting any findings to Microsoft Support." It's true that problems in DX9 games could certainly be down to the D3D9On12 layer, but it's also rather clear that Microsoft is through working on it. Furthermore, there's no reason rendering issues in D3D9On12 couldn't be down to a bug in Intel's own graphics driver.
Despite the majority of big AAA releases moving to DirectX 12, those aren't really the games people are playing for the most part. If we peek at the Steam player data, most of the top games going right now are based on DirectX 11. Intel probably thinks that DirectX 9 games are lightweight enough that the D3D9On12 translator will still provide sufficient performance, and that may indeed be the case. We'll just have to see when we do our own in-depth Arc testing.