Mineshafts for some reason now have oak pillars making them look like witch huts

With the new cave generation, I think that the pillars are somewhat a bit weird. I have 2 things to say:

1. If the pillars are not working as intended - Well then that's a bug
2. If the pillars ARE working as intended - These pillars are awfully long, and maybe the generation of mineshafts can change a bit.