The approach may be different, depending on whether it's fibre or coax from the street. Most are still coax.
They should bury it deep enough and in a conduit, but there are plenty of reports that cables have been damaged by routine gardening activities.
The contractors doing the work may look for an alternative route, by fixing the cable to a party wall or fence.
If you possibly can, it is best to be there to ensure the work is done to your satisfaction. But finding the date is difficult.
I buried a blue plastic water pipe in the garden with a trace wire for them to pull the cable through.