Sorry to hear about the accident and death.
I don’t think it’s safe for cyclists to make that right turn at speed, no matter what line they take. That hill is too steep and cyclists pick up too much speed to make that turn safely. Even if you stay in the correct lane, there can be pedestrians crossing Four Mile Run. I think it’s best for cyclists to slow down to a very slow speed before trying to make that turn. It wouldn’t be smart for a car to make that turn at 25 mph. It’s even less smart for a cyclist to do that.
As for the slip lane, I believe that it will be removed as part of the upgrades and design changes at that intersection. WashCycle had a recent post about it.