CNN Max is likely to evolve over time. Among the features the company will try out are ways of alerting Max viewers to breaking news while they are watching something else on the service, whether it be an HBO series, a Turner Classic Movies selection or an old episode of Food Network’s “Diners, Drive-Ins and Dives.” … Such features, he cautions, are not likely to surface when the service launches in September, but viewers will be made to understand that CNN Max will serve as a sort of “open beta for news” that will allow for experimentation.