If you no longer need a space to be available in multiple versions, you can.
When deleting versions, their associated change pages are deleted. The remaining pages will reflect the content from Public View, which is made up of master pages. In order to keep a specific version's content as after deactivating Scroll Versions, publish that version to the same space before deleting the versions in the versions overview.
We highly recommend making an XML backup of the space before deleting any versions, publishing individual versions to an archive space before deleting them, and checking the Content in Version Report to ensure you are not unintentionally deleting content.
When you deactivate Scroll Versions in a space, the space will go back to its original state – without any Scroll Versions related information or UI elements.