Hi! The below link says Lightning will turn on within 72 hours of Jan 7th 2020. After this date, will users still have the toggle switch to go back to Classic? If so, will the default landing page for users be Lightning on that date and they can switch it back to Classic?

https://releasenotes.docs.salesforce.com/en-us/spring19/release-notes/rn_cruc_lex_turned_on.htm

Thank you!