Not that
BTC needs any reason to dip but this is as good as any.
Mimblewimbles privacy is fundamentally flawed. Using only $60/week of AWS spend, I was able to uncover the exact addresses of senders and recipients for 96% Grin transactions in real time.
The problem is inherent to Mimblewimble, and I dont believe theres a way to fix it. This means Mimblewimble should no longer be considered a viable alternative to Zcash or Monero when it comes to privacy.
https://medium.com/dragonfly-research/breaking-mimblewimble-privacy-model-84bcd67bfe52TL no link clicky, Mimblewimble is supposedly dead

Well first of all I own NO Grin or other MW coin. The only alt i DO own in any sigificance is Monero, so there's the disclaimer...
But how many times have we heard about a cryptocurrency being toast? I tend to take these things with a grain of salt. On the other hand MW is a very experimental tech, and we should not be suprised when this sort of thing fails.
But why would this relative unknown coin be a reason for BTC to dip?
(one more thing... I am always amazed anyone would give any creedence to Zcash at all... the founders reward is reason #1 to shun it, and opt in privacy is not really privacy).