We're working on this feature currently and hope to add it back as soon as possible in the new results interface. You can still view the results of an MVT test, but you can't deselect specific sections (as of right now).
Let me know if you have any questions!
Good news! We've added back MVT section selections to the new results page. Now, you can deselect one or more MVT sections by going to the Baseline picker menu. You can also set different baselines there. The selection will apply to all the goal and variation modules shown.
Let me know if you have any questions on this!