Updated title of arxiv not recognised by Google Scholar?
Google Scholar should (relatively soon) detect both versions, at which point it will likely list them separately.  Once both versions are showing up in your profile, you can merge them together.  Select the check-boxes next to both publications, and a "Merge" button should appear amongst the buttons up at the top of the list.  During the merge process, you can tell it which version is the "best" version, and it will use the information for that version as the source for its title, authorship, etc.