Gerry Weinberg advocated just two options - will fix and won’t fix - and I would think twice before disagreeing with him.
In my view, testers should only express an opinion on Impact, and they may not even be competent to do that if there are effects beyond what they can see or are aware of. Everything else is the responsibility of the product owner. I personally refuse to to assign Priority or Urgency and I instruct my testers to do the same. If they are forced to assign Priority, I tell them to set all issues to the same value (I don’t care what value).
For bugs that are going to get fixed, priority should be set to maximise developer efficiency unless certain bug fixes must be released as soon as possible. Both of these are factors that only the developers and product owner can assess.
And to echo Michael, bug triage is really important. People who like to manage by numbers are doomed to fail (and I’ve worked for more than enough people like that).