This is really good and really bad news.
On the plusside, it really seems like running Battle.net is not a requirement, and it just logs in the bnet account once ingame. Two thumbs up. More availability and people being able to use Steam as a somewhat sensible launcher instead of the frankly annoying Battle.net, even better.
On the downside, I guess this also confirms beyond the investors call that OW2 is bleeding players quickly - and for good reason, since they've shown they cannot handle the fundamental design changes from the switch to 5v5 at all.