Yes, CM, I agree with you. But we must learn to read between the lines:)
When in 44.060, they discuss Packet DL TBF ASS in packet idle mode (18.104.22.168) they explicitly say that PACKET DOWNLINK ASSIGNMENT on PCCCH is followed by PACKET CONTROL ACKNOWLEDGEMENT (4 access bursts). And PACKET CONTROL ACKNOWLEDGEMENT is used to derive the timing advance.
When they say about Packet DL TBF ASSignment in packet transfer mode on PACCH (22.214.171.124.3) there is no mentioned about PACKET CONTROL ACKNOWLEDGEMENT.
See also Fig. C.1.