I don't believe this is at all related to BUG-000118472.
Smooth Line and some other cartographic generalization tools were recently enhanced with some additional options, I believe the performance bug may have been introduced at that time. Paul Dudley can you contact tech support with this issue, or post that data in a zip file for us to troubleshoot? I also see that the layer names used as input in the two screenshots is different, perhaps these contour datasets are different with regard to level of detail or vertices?
Thomas Colson the team is NOT aware of any global performance issues with geoprocessing in Pro. We fix individual tools like this geonet post describes as the reports come up, and as our testing finds issues. I don't believe I have heard any other report that all tools are slower in Pro, it is usually quite the opposite.