How rare is shiny scubachu?

I have been wondering if this shiny costume pikachu is as rare as other shiny costume pikachus like the shiny black hat pikachu or the shiny pikachu in the mimikyu costume because i’m seeing a lot of people looking for this shiny costume pikachu in their trade lists so it seems like this thing is extremely rare but the thing is tho it hasn’t been released again for two years and im hoping they don’t return it to the game ever again and i’m also assuming if it doesn’t return for another whole year then would that make it as rare as other shiny costume pikachus?