The current behaviour is really quite bizarre to many users. As reported by a user in http://forums.musicbrainz.org/viewtopic.php?pid=13612#p13612

Go to http://musicbrainz.org/freedb/misc/6d10ec08
Click import
You decide the artist in freedb is wrong, so do a search and select "Die drei ??? kids"
Artist displayed goes green, but text doesn't change.

I guess what it's done here is kept the original artist credit, but linked it to "Die drei ??? kids" in the database. This is really not an intuitive behaviour. The user wants, most of the time, for it to have changed the text - and expects it to.

(You can press the >> and /manually/ change the artist credit, but this is irritating if you're correcting bad data, typos, or bad attribution)

I personally think the philosophy needs to change - as this is very confusing to newer editors (and even me, to be honest). I believe diverting from "standard artist credit" to an overriden one for a release/track/whatever should be a conscious decision made by the editor because he/she understands the logic/philosophy behind artist credits vs. standardised artist names. Not making it harder for people to fix typos in imported releases

I guess this might be a wider case for MBS-2256 but it seems it's causing a lot of confusion, and I think worth discussing.