No idea if they are not but in my couple moose trips the butchers only dealt with one shipper so we just used whomever they had. If you're doing it on your own give a couple butchers up there a call and see who they use.
FWIW the butchering by
https://countrysidenl.com was superb. The butchering on the last moose was by
The butcher girls and it was truly a crappy job. Weird cuts and I don't think I've opened a package without a couple hairs on it.