How are younger objects outside our observable universe when the older CMB is an observer's temporal "edge"? We know the observable universe is limited to objects whose light has had time to reach us and that an observer very far away will see a slightly different (assuming cosmological principle) observable universe with a slightly different (yet similar) CMB. We know that the CMB (cosmic microwave background or surface of last scattering) was released everywhere in the universe at once and is considered one of the earliest images of the universe. If objects (galaxies, stars et.) created after the CMB are outside our observable universe, why is the CMB our temporal edge? In other words, how are younger objects outside the older CMB? I understand that the universe is expanding, but wouldn't the CMB get redshifted then too?
edit:grammar
The part of the universe that we can see is a cone in spacetime (our past light cone) and there are young and old parts of the universe both inside and outside the cone.
Here's a picture from Ned Wright's cosmology tutorial that shows what's going on.

We're at the top center. The red lines are (a slice through) our past light cone. Ignore the wavy $\phi(x)$ line and imagine a straight horizontal line there instead. Below that line the universe was opaque, so our observable universe effectively ends at that line (just like our view of the sun ends at its surface). There are young and old galaxies, stars, etc. both inside and outside the cone.