Updated Updating code using legacy Fluid APIs (markdown)

Updating-code-using-legacy-Fluid-APIs.md

@@ -8,12 +8,14 @@ For example, consider this import statement:
 import { ContainerRuntime } from "@fluidframework/container-rutime";
 ```
 
-In version 2.0.0-rc.3.0.0 and beyond, that import statement must be updated to be:
+In version 2.0.0-rc.3.0.0 and beyond, that import statement should be updated to be:
 
 ```ts
 import { ContainerRuntime } from "@fluidframework/container-rutime/legacy";
 ```
 
+_Note: The `./legacy` entry point was added in version 2.0.0-rc.3.0.0, but all exports are still available via the default entry point. Starting in version 2.0.0-rc.4.0.0, the exports are removed from the default export. This means you can upgrade to the latest patch release of RC3 - 2.0.0-rc.3.0.7 as of this writing - without any import changes, then update imports any time before updating to 2.0.0-rc.4.0.0._
+
 The Fluid Framework provides a tool to automate the rewriting of imports in your source files based on the current Fluid Framework packages installed. This command-line tool is distributed as part of the @fluid-tools/build-cli package.
 
 ## Installation