When you use ssget selection methods ("C" "W" etc. which detect objects on the screen) the objects selected are the objects visible in the drawing area at the time of evaluation of the graphical selection, newly generated objects are not recognized by ssget until the drawing area is updated.
RIGHT !
If you want to avoid updating the display list you have to merge the list new-obj-lst with the selection set ss2 as I suggested with my question:
[What do you want to achieve in the end? a list of VlaObj or a Selset?]