TBH I never considered the security aspect of asking people to load a strange webpage without their trusty Avast security extension to protect them. But now I do I can see the funny side.
Coriolis.IO is a much used and very useful website associated with the game Elite:Dangerous and, to the best of my knowledge, has no nasty surprises in store for the unwary. I’ve been using it for years. Those for whom this is insufficient reassurance will no doubt avoid it.
I’m certain no offense was ever intended by bob3160.
Just a degree of common sense and prudence.
For example, your link provided will not scan at urlquery.com. Site says, “Invalid URL or failed to DNS lookup.” So at least one third-party site cannot scan your site for malware.