Improve migration copy

Co-authored-by: Albert Yu <[email protected]>
Signed-off-by: Diego Andai <[email protected]>

packages/mui-material-next/migration.md

@@ -130,7 +130,7 @@ If you need to prevent default on a `key-up` and/or `key-down` event, then besid
  </Button>
 ```
 
-This is so the default is also prevented when the `ButtonBase` root is not a native button, for example, when the root element used is a `span`.
+This is to ensure that default is prevented when the `ButtonBase` root is not a native button, for example, when the root element used is a `span`.
 
 ## Slider