Of course it has not disabled support for JSONP (if it did, millions of pages would have been broken by now, since the mechanism is to simply call a function from a cross origin script).
But your specific case may be experiencing a Chrome bug (or a code bug :)).
Anyway, this group discusses the Developer Tools feature of Google Chrome and not general web development issues.
You can search
crbug.com for an existing issue and star it. If you cannot find one, file a new issue using the "New issue" link on the same page.
Please, do not add a "+1" or "Me too" or "Confirmed" (or similar) comment. It just wastes the time of Chrome engineers and sends unnecessary e-mails to all of the people who starred the issue.
You can reply with a link to the found or created issue and might get triaged (and fixed) faster.