if the response is a 301, there is no document served and therefore no meta robots noindex.
11:51 pm on Apr 1, 2014 (gmt 0)
Are you asking about a URL that was already noindexed, either via an X-Robots response header or an in-page "robots" meta? Or about a redirect from a formerly indexed URL to a new no-indexed URL? Is there a change in indexing status or only in URL?
Search engines crawl everything. A page with a long-standing noindex label won't be crawled as often. But it will be crawled eventually, and then they'll see either the noindex label or the absence thereof.