Can a turbofan maintain torque when spinning fast?
An initial thought is that at 10X the RPM, it is likely that the blades would be well into Mach numbers, which would have a negative effect on power requirements (that is substantially more torque in particular) to spin the fan, and more importantly the fan would not be effective at those speeds.  There would likely be blade damage as well from the loading.

However this is a rather hypothetical question, where if an engine were developed to do this, there would be other trades to be made in the design of an engine. Changing just one part of a system such as a jet engine, usually does not favorably alter the overall performance.