Where delisted stock go

I did a little financial clean up today before work. I called up my brokerage firm to do a few things that I couldn't regularly do online.

One is to move my US stocks (recently purchased) into my US account. This way when I sell them, I can either choose to keep the money in US dollars or change to Canadian dollars, just in case the exchange is really bad when I sell. If I planned ahead, I should have exchanged some US dollars to put in my US account when the rates are good so it's ready when I want to purchase US stocks.

Another is to get rid of a stock which now has been delisted, so that I could claim it for tax loss (next year). Basically it is transferred into an account where all delisted stocks go. Or that's how I understand it. What happens to it? I don't know. Why do we even need to transfer it in order to claim the tax loss? Isn't the fact that the stock no longer exist sufficient? If anyone knows the answer, feel free to share.