Most alt coins will definitly take a hit. But I think it will not not be as drastic. Some coins have already proven to be able to rise even if BTC crashes. Maybe it goes like this: day 1 altcoins fall 12%, day 2 they rise 18% and so on and so on.
If they don't fall as much as they rise, the direction is still up....
RE: BTC update 14.01.18