without a trace
Webmasters can do whatever they want with their domain names and websites. Migrating websites to different domains with little to no notice is annoying. Their rationale doesn't reduce the friction of a 404 (Page Not Found) screen or worse.
Consider dropping hints prior and setting up redirects after moving. Inject more object permanence into the digital realm. Empower your audience to find what they want where they expect it.
Keep in mind their desires and do what you think is best.