Fix the description of --keep-vars (#22386)

Author: vicb

src/content/docs/workers/wrangler/commands.mdx

@@ -311,7 +311,8 @@ None of the options for this command are required. Also, many can be set in your
   - Compile a project without actually deploying to live servers. Combined with `--outdir`, this is also useful for testing the output of `npx wrangler deploy`. It also gives developers a chance to upload our generated sourcemap to a service like Sentry, so that errors from the Worker can be mapped against source code, but before the service goes live.
 - `--keep-vars` <Type text="boolean" /> <MetaInfo text="(default: false) optional" />
   - It is recommended best practice to treat your Wrangler developer environment as a source of truth for your Worker configuration, and avoid making changes via the Cloudflare dashboard.
-  - If you change your environment variables or bindings in the Cloudflare dashboard, Wrangler will override them the next time you deploy. If you want to disable this behaviour set `keep-vars` to `true`.
+  - If you change your environment variables in the Cloudflare dashboard, Wrangler will override them the next time you deploy. If you want to disable this behaviour set `keep-vars` to `true`.
+  - Secrets are never deleted by a deployment whether this flag is true or false.
 - `--dispatch-namespace` <Type text="string" /> <MetaInfo text="optional" />
   - Specify the [Workers for Platforms dispatch namespace](/cloudflare-for-platforms/workers-for-platforms/get-started/configuration/#2-create-a-dispatch-namespace) to upload this Worker to.
 - `--metafile` <Type text="string" /> <MetaInfo text="optional" />