Touch preview removal on last iOS vers. update looks like it hasn't been a great idea. You are on time to restore it, one of the best Spotify features.
Updated on 2019-03-19
Thanks for coming to the Community, and adding your vote to this idea!
This feature was originally removed from the app due to low engagement. There was a statement at the time which you can check out at https://community.spotify.com/t5/iOS-iPhone-iPad/Touch-Preview-on-iOS-removal/td-p/1857905.
We're keeping this idea as 'Not Right Now', as it's not something we have any immediate plans to add back onto the app.
If we do have any new info to share we'll check back in here with a new status.