Its all really about timing and availability.
If you order/request a car as far away as August then most leasing companies will want you to get the lastest available plate anyway as its theirs when it comes back and a newer plate will have a higher (however marginal) residual value. Secondly, again, if Honda UK have a field full of
NHB Type S's MY08 and you order a
NHB Type S then unless you/they specifically request a MY09 then you'll be getting a MY08. The lease company will want you in your new car asap rather than waiting.