Jimmy Wales called Crypto a bubble which will pop sooner or later:
“...Right now, we are in a bubble, the cryptoworld is absolutely, definitely in a bubble. I don’t think there’s many people who would deny that.”Check
Cointelegraph article for details.
Look like Mr. Wales seriously plans to become a "whale" and buy some coins on the dips...
There are two possibilities that Jimmy Wales is planning its either to destroy bitcoin since he is really serious when he talks about it and the second possibility is your idea that he wants bitcoin to go down more so he can buy the dip. If we look at the chart there is another spike in a good volume that uplifts bitcoin from 8100$ to 8400$ in an instant possibly that was Jimmy Wales.
There is almost no chance for Jimmy Wales to seriously shake the reputation of cryptocurrency.
He is not considered to be a big market player or investor.