Yeah, that's formulated confusingly.
What it means is the new "RTX execution strategy" in OptiX, which is just a name for the new core OptiX 6.0.0 implementation. It's in contrast to the "mega-kernel execution strategy" used so far in all previous OptiX versions.
That new RTX execution strategy allows to use the RT cores inside the Turing RTX GPUs for BVH traversal and triangle intersection.
On GPUs without RT cores the bulk of that new code path will still be used for shader compilation, acceleration structure builds, multi-GPU support, etc. but the BVH traversal and triangle intersection routines run on the streaming multi-processors as before.
To invoke the hardware triangle intersection routine or a fast built-in routine on boards without RT cores, you'd need to change your OptiX application to use the new GeometryTriangles and attribute programs.
The GeometryTriangles neither have a bounding box nor an intersection program, but they have a new attribute program which allows to fill in your developer defined attribute variables, so that you can use the same any hit and closest hit programs from custom primitives in Geometry nodes as well as from GeometryTriangles.
Unfortunately the OptiX Programming Guide is slightly behind on explaining that. The online version hopefully gets updated accordingly soon.
http://raytracing-docs.nvidia.com/optix/index.html
The OptiX API Reference document and of course the headers contain the necessary function explanations and the optixGeometryTriangles example demonstrates the new GeometryTriangles and attribute program usage.