@pointoflife14 “False” has to be capitalized ☺️
But with modern Blender if you hold ALT when you click any checkbox (like Auto Texture Space) it will also check that box for all selected objects. Likewise holding ALT and clicking (or dragging) to select all texture size values will apply the entered value to all selected objects as well.
Which isMuch easier than the python method. BUT now you know how to write a little macro with python!