I agree with the increased capex. Norilsk's products are going to be in short supply over the next few years because of low worldwide capex. So the added investment will be value-producing. However, the foreign investors who set the price on a day to day basis probably do not agree. They have a higher discount rate for any Russian company than the large Russian shareholders do. So I expect some kind of move down when and if the new dividend policy is announced.
I also want to point out that Norilsk share prices seem to be following the price of palladium rather than the price of nickel. Norilsk gets about the same revenue from both, but nickel prices have been rather stable. Here's a graph of NILSY (in $US) and palladium over the last 100 days indexed to 1.00.
Long term there has been little investment in both nickel mines or in S. African precious mines. So I think prices will be a tailwind for Norilsk. There may be a switch from palladium to platinum, but I do not think it will be major.
As far as the Russian risk goes, I have posted before that I think the "new cold war" is silly and not in Russia's interest. But I don't make policy; I only react to it. So I do think that US-Russian tensions should abate, but only time will tell.