FWIW, keybase.io do the same; they store the root of the merkle tree into the blockchain with a similar principle of throwaway addresses, making it the whole database they handle basically unforkable.
Here's the doc on that: https://keybase.io/docs/server_security/merkle_root_in_bitco... . Since users on Keybase append their "announcements" (proofs, username announcement, etc.) to a public signature chain which is verifiable, the Bitcoin merkle step is designed to prove that Keybase is (a) showing everyone in the world the same thing, and (b) not omitting anything from the ends of people's chains.
