As long as the Pokemon is used enough in OU, it will be OU. Whatever the hell it does in UU, that's nobody's business.Scenario: Pokemon A and Pokemon B are UU and both have a specific niche in the tier. However, Pokemon A is viable in OU while Pokemon B isn't. A new version comes out (in the same Gen) and Pokemon B gets a new move that enables it to completely outclass Pokemon A in UU, but it still isn't OU-viable.
With that in mind, would Pokemon A be bumped up to OU because it is no longer used in UU but is still used in OU? If so, has this happened before?