Ahead of HBO Max’s launch next week, WarnerMedia Entertainment Chairman Robert Greenblatt has been walking a tightrope between drumming up and excitement and giving away the crown jewels. Speaking to an audience significantly more widely dispersed than the company’s launch party had anticipated, Greenblatt used his NAB Show Express virtual address to praise the “beautiful” front-end UI, the “perfect” back-end technology, and the “remarkable” remote workers who made it happen as the deadline fast approached. An experienced TV executive like Greenblatt should know better than to say a new service will run perfectly ahead of launch, although this is typical of a top company figurehead inexperienced in the intricacies of video streaming technology and even less experienced in how quickly…