Who knows? But if it does happens, there will always be the probability that people may start to turn their interests on Altcoins with unique features and more use cases and start increasing on their holdings - giving a much needed push to its value in the end.
Or it can also be with Bitcoin crashing down, most Altcoins may follow suit and fall straight down the bin.
Either way, anything is possible. We just can never tell.
Ha ha! Where do you see that happening again, if bitcoin drops to $5000, it means people are dumping and if they can dump bitcoin, what would make them invest in altcoin that they no longer find funny again. You already observe how bitcoin decline affects some altcoins, and how its increases also affect some altcoins too.
It means that the more bitcoin declines, the more it is possible for some coin to even go as low as zero when bitcoin turns to that $5000. The good news is that, I really dont see anything that will turn bitcoin to $5000 again, bitcoin has already grown past that stage and I think that the next value of bitcoin will be growing towards achieving the year's all time high of $13 to $15k on or before the year ending, I think $5000 is totally not feasible anymore.