Code is in place to ensure that all existing panel and canvas items are converted to their new forms, so you should not notice a difference, other than newly placed items now behaving properly from the get go.
We’ve made a versioning system in this update, where all items save the build ID of the game that the item was last saved in. That way, if we make a change that would otherwise break items that have already been placed in condos, the item code now checks the build ID that is saved on the item, so it can be converted to the newer state when a breaking update has been pushed out in the meantime.