updating rust release note based on PR feedback

docs/ReleaseHistory_Rust.md

@@ -14,7 +14,7 @@ This document contains release notes pertaining to the Rust crates.
 
 # UNRELEASED
 - DEP: `System.Text.Json` updated to `v8.0.4` to resolve Depandabot alert.
-- NEW: Introduces the `ScanEngine` struct, which now encapsulates the internal state tracking previously managed by the `Scan` struct. This refactor simplifies the usage of the `Scan` struct in scoped thread contexts, removing the requirement for a `Mutex` or `Arc`.
+- NEW: Introduces the `ScanEngine` struct, which allows simplified usage in concurrent scenarios---a single `ScanEngine` instance, along with per-thread `ScanState` instances, suffice without the need for additional synchronization. The existing `Scan` struct is operationally unchanged for users.
 
 # 1.5.2 - 07/05/2024
 - NEW: Added an initial secret redaction capability to the Rust package.