I am assuming that by plot's current zoom out point you are referring to the axes limits of the plot. It is possible to both zoom-in/out indefinitely in a MATLAB figure plot.
In order to zoom out of the axis limits, click on the zoom-in icon and then select an area outside the scope of the axes limits. Now, you can zoom out as much as desired by using the scroll button.
If after zooming arbitrarily, original view needs to be pulled back, you can right click in the figure and click on Reset to Original View.
Note: In case, it is not known, you can also zoom in/out along a particular axis using the Horizontal/Vertical Zoom options by right clicking in a figure and choosing the desired option under "Zoom options".
Hope this helps!
