AT&T U-verse → What is this?

Is this AT&T or something else? Why would they be digging up and uncovering whatever this is? Is this a good sign or a bad sign?

Probably AT&T, unless there is another carrier in the area.

Existing facilities are often "daylighted" so they aren't hit by new construction such as directional drilling. Around here a new crossing would typically be marked in white paint.

But could be lots of reasons, such as replacing or enlarging a pedestal or handhole, or surveying the ROW to see how much actual space there might be for new construction, compared to what drawings indicate.

The steel channel sticking up would usually indicate that a pedestal or cover of some kind goes over that hole.

The label on the cable reads "Superior Essex" which is a manufacturer of communication cabling.... they do make fiber cables, but they also make coax cabling for cable providers, among others. They also provide copper cabling for DSL type lines....

I can't make out any model numbers, but if you can, here is a link to their full product catalog: »superioressexcommunicati ··· 2021.pdf

Most of their FIBER products seem to have a yellow jacket, so I am not sure if this is fiber. Could also be coaxial or e.g. a 25 pair cable to hook up a ye olde DSLAM.

If you can find a model number on the cable, better identification is possible. Right now, it COULD be a fiber line, it COULD be a coax line, and it COULD be a bundle of phone lines....