It has been raised many times that ovens and hobs rarely state the maximum supply requirement, although since a fixed appliance nothing to stop them. In the main the 32 amp MCB is used for cookers, be it a hob or oven, that is the British standard, there may be a problem with a 45 amp MCB but unlikely with a 32 amp as it has been the British standard for so long.
In the main the MCB at the consumer unit is to protect the cable, not the appliance, since the appliance is fixed, the manufacturer could stipulate size, but only ever seen minimum size stated, and often you have a duel appliance outlet feeding both hob and oven, so it would mean that manufacturers product would have a limited use, so would be rather silly to state anything under 32 amp as it would impact on their sales.
Most cookers will have the installation instructions on line, so if worried look it up.
The problem is once reduced to 16 amp, how would a future installer know it could be returned to 32 amp?
