As a concept multi-tenancy implies that a single application or program has it's own character, including design, content and storage. On Academy X this holds true in the majority. Multi-tenancy allows a business unit, company, department, region (or unlimited granularity) to have its own "character". An Academy character would include a unique look and feel, login URL and learning units that are completely isolated from another tenant. This presents opportunities for customer and partner-specific portals.
A word of caution though: Academy multi-tenancy is not strictly that according to the definition as the Academy Administrator(s) will have access to all tenants which may pose a privacy risk. Multi-Tenancy extends to the App too.