Galaxies farther away than let's say z=2 are beyond our reach. If we today receive a message from such a galaxy, our response message will never reach back to them. So goes the current knowledge. This should also mean that sometime in the future, long before our response message should be due to reach that faraway galaxy, observers there should see our galaxy disappear beyond their horizon. Reciprocally this means that also we in the future will se that galaxy "suddenly" disappear out of our sight. But it can't of course pass through the CMBR. The CMBR must have been gone long before. So my question is: At what date in the future will the CMBR "suddenly" disappear beyond our - and for that matter anybody's - horizon?
I have no problem whatsoever with the CMB being everywhere, that is not even my point - the question is instead whether the CMB is forever, in the time dimension, not in the space dimension.
Again, I am not talking about "somewhere", it is about the time dimension!
So if we were observing galaxies approaching and passing through our horizon, they first have to transverse the CMB ("back to the womb")? Go backwards in time to "380 000 Anno BB"? The original CMB never gets older than that.