Yes. A configuration with no message body access at all is fully supported.
RelationLens finds contacts from message headers, calendar invitations and saved contacts. None of those require reading message bodies, so a configuration with no body access at all is fully supported.
Some customers turn on signature block reading to capture job titles and phone numbers. It is a separate permission, off by default, and bodies are read in memory only, then discarded.
See RelationLens.