This will not happen because bitcoin is the main crypto and all others are just altcoins to bitcoin. Yeah the market price for altcoins will going to move if there are also movement for bitcoin market price. So investors should look upon on bitcoin and not on altcoins. And it is better to hold bitcoins that holdings altcoins.
I don't think that's going to happen for another reason. The cryptocurrency market is very balanced. If altcoins exist then this is a necessity and is supported by demand. It is impossible to violate the laws of the economy with impunity. Bitcoin's image is high because it was the first. But altcoins have their benefits and therefore will always have bitcoin.