That IS weird because I did the update from the first page and mine also went from Telus A8182 to A8181.
EDIT - just realized you said you hadn't updated yet which means the phone is running a branded version, so the model number can say just about anything. Once you do the update, it should show the generic version which is A8181.
The language pack is slightly different as there is no Canadian (English) or (French) options, and no United States (English) option either.
I'm not too concerned about the language pack anyway as long as the phone works properly here (which it definitely does). I'm guessing the model number simply changed to the standard A8181 as that is the model used in Europe. The radio freqs won't change for us CDN/US users as I believe it's a hardware configuration for the North American market and software can't change the actual radio hardware.
As for locked status, you can do the update whether it's locked or not and the status doesn't change when you do an update as the lock codes are separate from the ROM firmware and specific to the IMEI number. Mine is unlocked and stayed that way when I did the update.
Now that this newer RUU is available though, I'm going to give it a try and see how it works later today and will report back.