I don't see why there couldn't be a legend that created an anti-scan AOE of some sort as an ability.
You would be correct on that assumption; We still need to consider if that would be degenerate in some way; and that the gameplay involving 'creating a fog of war' isn't just 'smokes' gameplay. But conceptually, there isn't a reason to say a character can't have a specific niche, in fact, I think it's a good thing. Creates a strong character identity.
That said, I feel there is a need for a hard counter to exist against combat intel legends as such. There are very few meta abilities in the game that have zero hard counter. AOE damage dealers, defensive zoning tools, personal mobility abilities, visual obfuscation tools, they all have a counter. Combat intel legends don't have that.
I don't want to jump into that conversation, but that would be an argument to nerfing/constraining scans systematically. I'm...