Roesler ran 1:59 and nearly 1:58 after Oregon's training regimen last year to become one of the very best in the U.S. She steadily progressed each year there and had no major injuries, so why change drastically? I could understand small changes, perhaps a little more mileage or something, but complete change seems silly. It's pretty obvious that there is no one magic way to train 800 meter runners, so why change something that was working?
I don't think there is enough evidence to say Rose Monday is a terrible coach. Maggie Vessey ran 1:58.50 and was sixth in the final at the World Championships while coached by Monday in 2011. She also ran sub 1:59 at least three other times and had a few other sub two minute performances. She ended up world ranked top ten by Track and Field News that year.
In 2012 while coached by Monday, Vessey was obviously not ready to perform in races up to and including the Olympic Trials. Given Vessey's complicated psyche that may not all have been Rose Monday's fault. It could have been poor coaching, but there could be lots of other factors. It is true that Vessey has yet to run as fast since leaving Monday as she did in 2011 while coached by Monday.
I hope Roesler can get healthy, fit and fast and get the World Championship Team position she is capable of. I do share some of the reservations about the coaching change, but time will tell.