Because it's likely that someone signed and NDA and posting those images violated it. Taking it down was necessary, even though nothing really dies on the Internet.
At the least there are some upset people at Uniden. The person who posted that might find themselves disinvited from future events.
As I recall, Uniden doesn't exhibit at CES, but they do have a by invitation only "Hospitality Suite", where there might be some sneak previews. Since CES was only a couple of weeks ago, it's possible that where the images came from.
In some parts of the country both NXDN and DMR are used for public safety. Both are much less expensive than P25 equipment and some agencies don't have the money for P25.