Sorry if this sounds annoyed, but I don't know why people think symbolic nothings like this will be important to the story. They never have been, like ever.

Maybe it's because it's been 10 years since ADWD, but I legit wonder where people got this idea that GRRM ever, ever uses such a trite plot device to conclude an arc.

If the rubies have any relevance at all, it'll be because someone is at a jeweler that is claiming to have the Rhaegar's 7th stone, which we know hasn't been found. Or that one of the the Septon's helpers pocketed it, and maybe we'll hear some reference to a young monk from the Quiet Isle murdered in a brother for a ruby.

The idea that the rubies are going to have anything to do with anything important doesn't just seem unlikely, it seems actually antithetical to the series so far.