If anyone is interested this is the response from MathWorks:
After discussing this with my colleagues, depending on your use case, there are a couple of things that may help achieve this:
Considering your example of three listboxes, you can set the "enable" property in the property inspector for that listbox which needs to be reachable only using the mouse to "inactive". This will effectively limit the tabbing between the remaining two listboxes. However, please note that setting to "inactive" will make this uicontrol not operational. You can learn more about this property here:
https://www.mathworks.com/help/matlab/ref/uicontrol-properties.html#property_Enable
Alternatively, you can set the tabbing order between the listboxes using the "tab order editor" and then use "tab" to cycle forwards and "shift + tab" to cycle backwards. You can learn more about this here:
https://www.mathworks.com/help/matlab/creating_guis/setting-tab-order.html
However, currently there appears to be no direct way to achieve a workflow where all three uicontrol elements are active and yet being controlled selectively from the keyboard and the mouse.