Preloading authorization data into memory does not, by itself, provide the specific security guarantee (consistency) that defines Zanzibar.
The Zanzibar model is famous not just because it is fast, but because it solves the "New Enemy" problem (or causal consistency). Simple in-memory caching (preloading) often fails this test unless it is paired with complex invalidation logic that mimics Zanzibar's Zookies.
Preloading authorization data into memory does not, by itself, provide the specific security guarantee (consistency) that defines Zanzibar.
The Zanzibar model is famous not just because it is fast, but because it solves the "New Enemy" problem (or causal consistency). Simple in-memory caching (preloading) often fails this test unless it is paired with complex invalidation logic that mimics Zanzibar's Zookies.