It's would be very much in the others best interest to show the 2ohm figure, if it is a good spec, and almost doubles from 4.
The only reason I can think of not showing a 2ohm spec for any expensive SS amp, would be, either it is Mosfet output or Class D. Both these give poor 2ohm specs when put up against their 8 and 4 ohm specs.
Cheers George