Hi Alex,
I think some CJ owners/operators would be very upset to have them described as VLJs since they look down their noses at the likes of Eclipses!
Seriously though, Looking at the TCDS for the CJ, under EASA Certification Basis Paragraph 3 - Special conditions you find buried in there:
performance, including takeoff, takeoff speeds, accelerate-stop, takeoff path,takeoff distance and takeoff run, takeoff flight path, climb one engine inoperative, landing, balked landing,climb
So they have been required to do the performance to CS-25 standards.
The identical wording also appears in the FAA TCDS, so it is not a condition imposed by EASA. Certainly i remember the AFM saying performance is to Part 25 standards long before EASA was thought of.
Hope that helps!