[Grammar] the truck arrives/is arriving on

[Fagin]

We were told that when talking about future scheduled events we should use Present Simple and when about future arranged events - Present Continuous. I cannot decide if in the following it is a scheduled or arranged event:

As far as I know the truck arrives/is arriving on the 12th of September. We need to unload it immediately.

 

[GoesStation]

Either option is fine.

 

[Raymott]

Yes, we say "The train arrives at 1.57pm" but "She's coming at two o'clock".
But it's impossible to tell from your sentence which is appropriate. Is the truck regularly scheduled? Would it arrive on that date regardless of your load? Did you arrange it, or are you using a regular trucking service?

 

[Fagin]

But it's impossible to tell from your sentence which is appropriate. Is the truck regularly scheduled? Would it arrive on that date regardless of your load? Did you arrange it, or are you using a regular trucking service?

This is from a test and there's no more information available.
I was asking exactly these questions and indeed it looks like the question in the test is stated ambiguously. I've posted it here to ascertain this.