I think this should be reverted, and a fixme="probably stream; needs field checking" tag, or some such added.  It seems 99% likely that someone was intending to add a stream and made an error.

Why do you think it is ok to just delete, rather than comment on the original changeset and ask?   The point of OSM is to work together to improve the map database (and the surrounding infrastructure), and just deleting doesn't really fit that.