Future plans would, by definition, be unreleased product, so that does not count.
It may indeed count - lots of products have latent features included specifically to support future developments or accessories, or interoperability with perhaps some other product or service which is still in development.
A car manufacturer may very well 'consider' his design to be a secret, but once the car is available for sale they can't successfully claim it IS a secret
The "car's design" may not be a "secret" in the most casual sense of that term, but there may be software features, or other aspects of things like interface design that are not yet put to work because new options are coming down the road. Even if a not-yet-used feature or interface is patented, that doesn't mean that knowledge of it or how it might leverage other third-party deals for new behavior or features isn't considered very much to be sensitive information and exactly the sort of thing you'd want to discuss under and NDA. I may have a patent on something, but that doesn't mean that everything I have to say with prospective partners or employees or retailers is something that I consider insignificantly strategic or sensitive to want to protect.
The only way an NDA makes sense in this case is if they planned to have every person who entered one of 'their' datacenters, for all eternity, sign an NDA
Just because you can walk into a datacenter doesn't mean you'll understand, by looking around, every last competitive detail about how things are being done under the hood.
I have a pile of equipment running in a datacenter. There's a two-way NDA in place to protect both their operations and mine, not that either of us are doing anything terribly exciting. Sometimes the NDA is there just to keep the overall nature of the business arrangements or financial information from being disclosed. For example, I don't want MY customers to be able to pick around and find out what I pay for my co-lo space. Likewise, my datacenter doesn't want me to write a blog describing their internal security operations, or what I pay for the particular deal we struck three mergers/acquisitions ago.