The doors could be easily changed and an amoire used instead of a closet, so my guess would be that the advertising is within the "norm" for that area. Sometimes the listing will have pictures or maybe notes that say "non-conforming" on them.
It is not up to the MLS regulation coordinator to define a bedroom, as it is up to the city. This is commonly mistaken by agents. If the bedroom conforms to the city's definition, it can and will be called a bedroom by the MLS. I hope this helps.
It seems as though there is a lot of talk about the cities defining bedrooms and while that is helpful and useful, it is up to the MLS to define a bedroom when it comes to "listing" a property. Have your agent send an email to the rules and regulations administrator with the local MLS system requesting they review the listing that you saw.
You might also ask your agent for the MLS's definition of a bedroom so you can know what to expect when you are out looking. Keep in mind however that it is up to the agents and consumers to police the accuracy of the MLS data, nobody from the MLS it touring these properties to check compliance so there will be instances where you find an agent who is trying to sneek one by to get a leg up for their client.
Good Luck in your search.
Olmsted county defines a bedroom as egress window+door+closet. When homes are listed incorrectly we ask the listing agent to make the correction. The house you viewed appears to be a 3 bedroom plus office. You can contact the MLS office (probably the Southeast Minnesota Association of REATLORS) to report the error.
However, most consumers expect an egressable window, closet, door, walkable ceiling height (7'+), at least 9' x 9'.