I ended up contacting Matlab Support for this.
Some of these parameters are formatted based on another parameter. While the LastModifiedBy, LastModifiedDate , and ModelVersion parameters are read-only, you can change their values by changing their corresponding "format" parameters.
For instance, to change the name of who modified the model last, i.e, the LastModifiedBy parameter, you must modify ModifiedByFormat and save the model for the change to affect the LastModifiedBy parameter.
set_param(sys, 'ModifiedByFormat', 'Ada')
A summary of how to change all the values in the Model information section of the model properties is given in the table.