As I understand it, money was spent to extend service on v5r4.
If you look carefully at:
You will see there is a program extension available.
It has been enhanced in V5R4. Prior to V5R4 the support extension was
basically "You send IBM the check, IBM cashes the check. If you call in
with an issue, and we've already generated a PTF for that, we'll send it
to you. If a new issue pops up, like a previously undiscovered time bomb
that causes all machines to IPL every hour on the hour after a certain
date, then that is not covered. Thanks for the bucks."
V5R4 has gotten a little better.