"Shireesh Thota, corporate vice president for databases at Microsoft, ... did not answer questions about pricing for the various Azure PostgreSQL services."

Don't care a whit about this until they provide enough info to comparison-shop it against other competing products.

HorizonDB sounds interesting, but it’s hard to evaluate until Microsoft clarifies how it differs from their existing Postgres offerings (Flexible Server, Hyperscale/Citus, CosmosDB integrations).

Without clear pricing + performance characteristics, it’s difficult to know whether this is a new architecture or just another SKU in an already crowded lineup