Perhaps AT&T is planning on moving the content to a streaming video service of their own in the near future. It looks like they announced a couple months back that they would be launching a new streaming video service in late 2019, so they might be planning on uploading these videos as filler there. That, or they simply don't want their content generating revenue for a competitor's service.
That revenue projection is peanuts if they had to actually pay for staff to manage it to say nothing of the cost of acquiring the IP to begin with. Clearly, this is a case of buyer not knowing how to manage the IP or having inept management acquired.
Of course, it could just be that this was a flash in the pan for tech entertainment and people grew tired of the genre.