The propagated clock latency is nothing but network latency i.e latency from clock port to your clock pin of FF.
source latency is the latency form clock source to your clock port.
Before CTS, clock uncertainity constraint includes this network latency + jitter
After CTS, no need to add network latency(clock uncertainity is only jitter now) it is included if you use propagated clcok.
Added after 4 minutes:
The propagated clock latency is nothing but network latency i.e latency from clock port to your clock pin of FF.
source latency is the latency form clock source to your clock port.
Before CTS, clock uncertainity constraint includes this network latency + jitter
After CTS, no need to add network latency(clock uncertainity is only jitter now) it is included if you use propagated clcok.