Very unlikely - if the bolts thread into the motor casing, generally these holes are tapped at the factory.
They may also be held with nuts (self-locking or otherwise) and simply pass through the motor casing brackets. I’m thinking this may be the case here, as DaveC has mentioned elastic suspension as a means of reducing vibration/noise, and that would be more effective if the motor were ‘free’ to move on the bolt shafts rather than being a piece of the fastener. Before you start unscrewing, I would recommend you locate any nuts on the inside of the machine and make sure you can reach them to hold them with a tube wrench, a pair of long nosed pliers or even just your fingers. Nothing more annoying than starting to unscrew, finding out that the other end is ‘free’ and you can’t go forward or back, but you now have a substantial piece of metal moving around in the machine (even if constrained).
