Good for them. By doing this they've really thrown a monkey wrench in the whole process.
Any party that backs a Native exemption and then upholds the gun registry for the rest of Canada, will look like they're giving the country away to the natives and have decided that a discriminatory policy against white Canada is perfectly acceptable.
But, if they don't back the Native exemption they'll be labeled racists, lose votes and have to watch the Canadian Government taken to court for violating Native Rights.
Either way it's a win win situation for abolishing the gun registry, traditional native hunting weapons not withstanding.