In a sense, yes. Something that is omniscient would have a perspective so utterly alien and different from the very limited perspective of humans it is not at all hard for me to surmise that an omnimax deity would not have the same understanding of evil as humans do. And that is generously assuming that concepts like "understanding" and "evil" would even compute for such an entity in the sense that we understand them, which isn't an assumption I'm necessarily willing to grant either. Based on mystical experiences I've had, it... well, let's just say point of view and perspective very dramatically changes one's understanding and perception of reality. This is apparent even without such mystical experiences if we just look at human cultural diversity and the stories humans tell. If humans have such diverse perspectives on reality, what does that suggest about an entity that can see all perspectives at once? Something impossibly beyond human comprehension, that's for sure.
In my view as a non-monotheist, the problem I see with the monotheist omnimax god-concept isn't the framework in of itself, but when humans start proclaiming they know what this god "thinks" or "wants" (as if those terms can apply). Seems to me the god-concept is inherently incomprehensible and numinous; so utterly greater than everything humanity can ever grasp that to say much of anything about it at all is folly. It's part of why I have no interest in such a god-concept as I find it an unworkable foundation for any sort of practical religion. That doesn't stop its worshipers from trying, I guess, but I find it very confusing as a polytheist whose gods are far more approachable and comprehensible.
