I would say to be cautious with any potential rumour but realistically you're never more than a couple of months from a Call of Duty game, so I'm going to say this tweet from Jim Sterling is probably legit.
It's looks like it's referring to the point of sale cardboard signs retailers usually put over the till and shelves and that third of May date suggests a reveal is due any minute. The current set up has Infinity Ward, Treyarch and Sledgehammer tag teaming releases on a three year cycle and this year will be Infinity Ward's go.
The studio’s last game was Modern Warfare 3 but whether we see a continuation of that, or the start of a new franchise is the big question. In 2012 the voice actor for Captain Price (the series' most recognisable character) supposedly said he was meeting with Infinity Ward for Modern Warfare 4, something the studio very strenuously denied.
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