While I only named .xyz above, my (enterprise) company blocks several other TLDs as well like .info, I'll check .icu when I'm back after holiday but would not doubt it's blocked. Corporate IT subscribes to some sort of hosted service, I would not doubt other companies are using this same service (name-brand).
I think it's just part of some generic category of strict blocking used by the hosted service - there's a lot of other stuff blocked, we generally don't get reasons as users other than it being the corporate security posture. We are a business partner of many firms (some have high security due to their needs) so our company trends in that direction - maintaining compliance is a big deal, entire team(s) manage it at various levels.
Do you know the name of the service? Blocking .xyz names as a whole would cut your company's employees off from accessing sites like Engine.xyz, ABC.xyz, and Starship.xyz.