The price getting dumped is a result of global exchanges' average price for Bitcoin, which is reflected from the Buy/Sell orders on these exchanges. Once the pressure on buyers is high (few sellers @ stagnant higher prices), the price starts to increase.
Unless these 4040 BTC is sold in exchanges in batches, and with prices stagnant and drives the price lower, it could actually dump the price. But this type of news selling those coins in auction, might get huge attention and drive the buying force (buy orders) higher.
Yes, it is like free advertising for the bitcoins. This may pull some new buyers. Even if prices go down, it may be for a short period and it will come back. If one is already in crypto markets for long time then they know that all these things will not impact much on the bitcoin prices in the long run.
If they are selling at much-discounted prices then for the short term we may see prices correcting for a while. If not, I don't think it will impact much on the current bitcoin price.