I don't think it's necessarily about being bullish or bearing....

I don't think it's necessarily about being bullish or bearing. Given no one knows where gold will be 1-5 years time as it doesn't pay a yield and we don't know what the state of the world will be like then, I think it's useful to see if the company still stacks up in the event prices do decline at some stage over that period.

I'm a bit skeptical of assuming forward rates greater than the spot rate for each of the next few years. They could have instead used futures prices, but they are lower than $1300 so wouldn't look as good in their DCF.