They are still there. From v6.5.0, they are hidden by default. Use the Window menu to show them (option: ‘Show Text Pane Selector’): see more. The setting is a doc level, IOW you’ll need to turn it on just once for any TBXs that use export.
My assumption is this change occurred because those of us who use export (myself included) are in the minority and on small screens the selector controls rob display space in the text pane.
Although the change is documented in aTbRef (link above) I don’t think it got added to the app manual itself.