PRL or prefered roaming list, is basically, just a list of towers that
are the least expensive for sprint to use based upon whatever contracts
Sprint has with the tower owner/service provider.  If the service
provider is still there, and the tower has not been removed, then you
still should be able to use the analog signal as long as you have at
least a dual band phone.  However, if there are any other signals in
the area at all that are on the PRL, the phone is going to seek them
out 1st.  most phones have a way to change the settings, to where they
will do one of the following things. a. seek out only sprint service.
b. seek out only roaming service.  or c. whatever is availabe
[automatic].  Theoretically, the analog provider should still be
available to use even if it is not in the PRL as long as they are still
doing business in that area.  There are some places, and some providers
that if you picked up their signal, you would be required to give them
a credit card number to charge your calls to.  this is called manual
roaming.  I hope this clears up the issue a little bit

It depends on the PRL entry.

If the aalog carrier was simply removed from the list, then it's
possible IF there's no other signal available.

If there is a NEG entry for that SID in the PRL, then the phone is
instructed NOT to roam on that carrier under any circumstances except
for 911 use.  In this instance, the phone will not lock on to that
signal, even if there is nothing else.

Agreed....
But I have found places that the ONLY place I can roam on is Analog.
It appears there are some very very rural places, that all you get it Analog
for roaming....
That is why I still stick with the multi-band/Analog phone...