Hello,
I think #executeMethod was a shortcut for method without arguments of the method #withArgs:executeMethod:. I missed it too, so I guess you can add a bug report, create and commit a slice and lastly it will be integrated in Pharo in the next few days.
#withArgs:executeMethod: is implemented in ProtoObject, but we take care not to have too many methods there. This kind of facilities are usually in Object (For example, #isNil is in ProtoObject, but #notNil which is a facility for 'isNil not' is in Object). So I guess what you miss is:
Object>>executeMethod: method
� � ^ self withArgs: #( ) executeMethod: method
Best,