If you fly an approach above VMC minima, separation is ultimately your responsibility. Below, it is ATCs in controlled airspace.
If there is a CATIII ILS and no NOTAM or other information from ATC, then you can assume it is available. Although if the wx is below what‘s available, ATC should ask the crew‘s intentions anyway.
You also have to assume that everyone knows and does their job, but be aware that threats and errors (inc procedural ignorance) exist and happen: “You can always attempt an approach…” heard that corker a few times.
As megan said some posts back, the FedEx crew were cool as cucumbers and dealt with a near catastrophic situation very professionally. The other crew declined the early turn and should have said “unable“ not “negative“, but hey, the crew flew the aircraft and the day was saved.