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).
Never really trusted grin and mimblewimble so doesnt make much difference to most and shouldnt to the btc price.
There is something called snicker which is interesting if you would like privacy on the side of bitcoin in the morning with your breakfast.