Canonically? Yeah, absolutely. Perhaps "was" is a better term to use... But he definitely still has his moments, constantly. Such as his really disturbingly aggressive Hemoloyalty. But he's not really outwardly "angry and aggressive" in the traditional sense... Anymore, and for now. I might've mentioned this earlier, but Horuss's smiley demeanor is actually a facade forced upon him by Meulin.

This whole "Smiley Horuss" deal is a very recent change, in text. Very, very recent. It occurred in the advent of Horuss and Meulin becoming Moirails, which occurred in the advent of them meeting Equius and Nepeta. They saw their Moirallegience, and wanted what they had, basically.

Anyway, this Moirallegience meant that, in true Meowrails fashion, Meulin was the one keeping Horuss in check. But... Meulin has a rather unfortunate problem with Toxic Positivity, actually, which was a very common issue amongst Tumblr users for a while, especially people heavier into the fandom side of things... And this is what lead to Meulin forcing the facade of constant happiness onto Horuss... Essentially as "treatment" for his anger issues. She seems to be under the impression that it is somehow healthier to force yourself to never experience any negative emotion, ever, than it is to be able to confront and healthily engage with your negative feelings. Which... Again, is just what Toxic Positivity is, and again, was a huge problem on Tumblr for a while. It's a unique form of the Anti-Recovery mindset.

As the above screenshot says, Horuss finds this mask to be putting him in constant agony. It's really not helping him, and he's still an asshole. He just happens to feel more like garbage constantly for it. He isn't addressing a single one of his issues or bigoted views, he's just smiling while expressing them. For once, Meenah is the Voice of Reason regarding this: