The collector current in the graph is measured for 80uS pulse duration.


Does this mean longer or shorter durations have very different Vce values?

 

Nope, it means it had to be measured during such a short pulse, otherwise the IGBT would probably release its magical smoke.

 

It would exceed its SOA parameters?

Either that or its thermal rating.
For example, from the graph, Vce is 3V @ 100A , which is 300W.
It's unlikely the device could handle that continuously, even with a good heatsink.