It doesn’t matter what BRICS wants or says regarding reserve currency. The only voice that matters on this topic is OPEC.
The way I read the article the BRICS are not making an attempt to eliminate the $ as a reserve currency, but to diminish the status of the currency.
For example, the article states that: “The five countries agreed to expand use of their own currencies in trade with each other — an important step toward putting the dollar into a new downsized place.”
In addition, don't be so sure the up and coming economies of the BRICS won't have a significant influence should they collectively push to dethrone the dollar.