@Ally ***********
Meaning they will accept BRICS payment (whenever they agree on one) but they are not going to stop using the Dollar & Euro (the currency of there biggest markets). If they say so, they lie. And, in the end, they may change their announced intention (they frequently do) if it looks like the BRICS currency is a Lead Balloon.
They are just keeping their options open but just watch. With that subset of countries it is more important to see what they do. Not what they say.
But still, look at the countries that are all clamoring to join the BRICS. The inclusion of most of them will bring any prospective currency down, not up.
Btw, the "Rich" countries you mention are, primarily, politically unstable.