Shimano's Direct Mount Derailleur: What's the Difference?

Shimano's 105 is quite different in the way it's placed now. Bikes have got way more expensive. If there was a rim brake 105, that would leave it as the sole rim brake option in Shimano's catalogue. It does seem like they're just abandoning rim brakes. To be fair, we haven't actually seen drop bar shifters. We know they're coming. Like Shimano's hinted as much and they've been typically vague, but it will come. There may well be rim brakes as part of that.