I've been checking a few different seeds and I am finding that sweet berry bushes do not seem to generate inside snowy taiga biomes, while they DO generate in regular taigas. Two easy seeds to observe this phenomenon on are -1568938760628874508 and 4686004408549520578. Seems like a bug!
MC-257860
Sweet berry bushes are extremely rare in snowy taiga
Resolved
Works As Intended
2
I was able to find one patch after searching for about 1500 blocks in a single biome world. Looking at the code, it seems that it is intentionally much rarer to find patches of sweet berry bushes in snowy taigas than in regular taigas, so this might be intentional.