Whilst related, they are different settings for the "computer". The speed would be related to cost index, which the airline specifies for each flight. That speed would indicate that they were most likely trying to make up time, or someone went rogue and was flying faster than plan.
The climb thrust is a separate setting, and is usually dictated by company SOP and default settings.
The aeroplane will only wash off the reduced climb thrust very gradually if at all. So by flying away from the best rate of climb speed (which is most flights by differing amounts), these climb rates are all that you are left with, unless someone manually adjust the climb thrust in the FMS.