The MCC's new code regulating the maximum size of a cricket bat arrives October 2017.
The Maximum width of the bat will remain 108mm or 4 1/4 inches, however the apex will be limited to 67mm or 2 41/64 inches and the edges 40mm or 1 37/64 inches.
The law is being introduced to address the imbalance between bat and ball. However, it really gets down to the density of "timber" when looking for greater rebound... so in real terms, size will not matter other than it may reduce the "psychological' goings on, in the mind of some with, ball in hand.
English Willow by the Willow Blue Cricket Forestry Project... "because it is the best"