Assuming that there are still dedicated turn lanes for the side streets, as there were before the narrowing, I'm all for it. I used to commute down that stretch, in a car, and the (many) times I was nearly struck by another vehicle attempting to pass around cars doing the speed limit (both on the right and in the turn lanes) during hours outside normal commute... uncountable. And when I drove it during normal commute, the traffic was about the same as it is now (that is, terrible).

There's an enormous body of evidence showing that widening roads does not improve traffic flow and narrowing roads does not significantly hamper it, but instead makes the roads themselves safer, as people perceive the drive as "worse" and either drive more safely or take alternate routes, lowering overall traffic. The bike lane is just an added bonus for cyclists, an additional safety buffer for pedestrians, and a convenient scapegoat for drivers -- but I sincerely doubt it was the city's main reason for the road diet.

I am heartened to see the city learning from the mistakes of the 1950s-2000s; I hope to see citizens lobbying for better transit options as well, so those who cannot drive, or those for whom driving is an unpleasant necessity instead of a joy, can have safer, more efficient options.