The 'company/deals/ticket/attachments/etc.' column was hidden before. Now it unnecessarily occupies valuable screen area more efficiently, for me, used to view correspondence/tasks/notes. How do I hide that column and return to the (2) column view as the default?
This has since been removed, as the right sidebar being collapsible added close to one second of the page's load time on a record—so the team has removed it. Definitely a contentious change, but one of the top priorities for the contact record pane has been to improve loading speeds, and this was the #1 slow-down on the page.
However, I know our team is still reviewing any feedback on the change and I would encourage you to post your thoughts on this post here.