There's so many hype and noise about this GBTC unlock, I don't think it will have a big effect.
And if ever they sold, do you think they will not buy back again when the price hits below $30k?
It could fit the bearish narrative that we are experiencing right now, but I doubt that it will have a long term effect.
It's a big thing because it means that we can anticipate that the prices are going to go down and when the prices go down, we will be able to buy bitcoin at a much lower price so yeah it has a big effect.