Automatic migration to RSTP

[bobdempsey]

In the 7th ed on pg 538, the last paragraph in the RSTP section says:

... once the Core switch knows to send 802.1d BPDUs ... it won't change this automatically if the S1 and S2 switches were later configured with 802.1w ...

It seems to me that I observed that my root did, indeed, switch to W BPDUs without an access-layer switch reboot:

Root switch after rstp on the root and before rstp on the access:

 
c3550-router#sh span vl 1
VLAN0001
  Spanning tree enabled protocol rstp
  Root ID    Priority    24577
             Address     000b.be30.c380
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
  Bridge ID  Priority    24577  (priority 24576 sys-id-ext 1)
             Address     000b.be30.c380
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300
Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/24              Desg FWD 19        128.24   P2p Peer(STP)

Root switch after enabling rstp on the access switch:

 
c3550-router#sh span vl 1
VLAN0001
  Spanning tree enabled protocol rstp
  Root ID    Priority    24577
             Address     000b.be30.c380
             This bridge is the root
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
  Bridge ID  Priority    24577  (priority 24576 sys-id-ext 1)
             Address     000b.be30.c380
             Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
             Aging Time 300
Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Fa0/24              Desg FWD 19        128.24   P2p

Is this quote now incorrect on the later IOSs? I'm running at least 12.1(22) on both swithces.