Let me elaborate on my perhaps flip-sounding, short-lunch answer.
While one can (always) ask for more specifics, it's good to know that consideration was given both to keeping the bottom deep and robust (that's how I'm reading "opened up") and to giving speakers some protection.
As far as EQ, I don't think I tend toward ruler flat (It would be interesting to see a graphical representation of how I EQ various amps), but I do like it as a starting point. As I mentioned in another thread, with basses, pickups, and cabs already being voiced, I'd rather have one less layer of voicing to worry about. If an amp has a very pronounced or " bumpy" voice, then, in my experience, it tends to be more picky about cabs - and vice versa. As I also mentioned in that thread, I've found that I tend to prefer cabs with a slight rise in the mids. (Never said I was perfect!). There are lots of amps I like and I'm aware that there are very few without some baked-in voice, so having one doesn't mean I won't like an amp - maybe a lot - but I've played through one or two supposedly flat-or-close DI/preamps that I liked a lot, too.
In any case, there a lot more that goes into the feel and sound of an amp than a frequency response plot.
Thanks again for your feedback and input in this thread.