That policy has been insitu for quite some time now, well before Richard's time.
I see the merit in this policy so that these travelling players contribute to regional cricket, benefit the fans etc. Contributing to the development of cricket as playing with these experienced players could serve to motivate younger lads.
If these are the rules then they are not eligible but the WICB is shooting themselves in the foot.
That said it gives opportunities for other upcoming players but would happen if they are any good is that they will be snapped up by a franchise and you are back to square one.