In OZ at least, if you're cleared the approach, your cleared to descend as required (in accordance with minimum alts etc. if in IMC)
Mig3, we were in descent to FL 80 and told to proceed direct to an iaf, and we were not on an arrival. Immediately after that we were cleared for an approach well before reaching the iaf. In Australia then, is MSA included as one of those altitudes you are now cleared to descend to once withing the specified distance?