I'd like to know what happens if someone owned GBTC shares before the fork, and sells their shares before the distribution of assets, if they'll get theirs.

Edit: The way I'm reading the following, if you bought shares by end of day July 31st, you should be entitled to whatever they distribute.

"In addition, such distribution, if and when made, would be to owners who held Trust units on a specified record date, which is anticipated to be the day the fork occurs. The amount of any distribution will be net of expenses of the Sponsor and the Trust, including costs associated with liquidation and distribution."