nope. the actual reality is
someone deposited 8000btc into coinbase pro

maybe that someone sold some of those coins but not all..
coinbase pro's volume for the entire day of all traders is $127,627,412 = 2320btc

coinbases daily trading volume average is ~$200m=~3600btc

so with there being an 8k btc deposit. expect either a sell off to a factor of 2-3x daily volume either quickly in one day or slowly over multiple days

..
heck the wallet movement may not even be a user.. it can just be a hot/cold wallet shift internally