What about Customize the map scale list?
I don't have Pro on the machine I am working on right now, so I can't tell whether a map scale can be explicitly forced like the check box does in ArcMap.
UPDATE: Well, it doesn't appear there is a way to force zoom scales.
I landed here looking for this functionality. It's unfortunate all of the little things we took for granted in ArcMap that haven't (yet???) made it to Pro.
I'm working with a local basemap, and it would be really nice to have my zoom be locked to the scale levels of the basemap caches.
Only Display These Scales - in ArcGIS Pro is an idea that has been reviewed on the site.
There is an equivalent enhancement request [ENH-000103234: Add “Only display these scales when zooming” functionality to ArcGIS Pro] which is marked as In Product Plan. We can probably update the Idea's status to keep them in step. Unfortunately I don't have a timeline on when we'll see this but looks like we'll get it into a future Pro release.