The presumption in the writing community is that attorney's fees will be taken out of the $3000, but I haven't seen that confirmed. I also have not seen anything confirming how much the attorney's fees will be.
Splitting the payout with the publisher 50/50 seems to be the default. I looked over my contracts to see whether this was true for me. My subsidiary rights clauses specify a 50/50 split for most rights sales, but I didn't see anything on the list of specified rights that I thought definitely applied in this case. My agent, however, said that the 50/50 split applied in my case, so that's what I put on my claim, since she negotiated the contracts and presumably knows. (Interestingly, I know of no route for agents to be paid. My agent has gotten her 15% for things like audiobook sales, but I don't think this is the case with the Anthropic settlement.)
Some publishers, including big ones like Wiley, are trying to take 100%, which is unconscionable. Those writers' claims, and those of writers who didn't go with the 50/50 default, are finding that their claims are being disputed by their publishers. Will this result in lawyers' fees eating the claims up? Nobody knows, but it will certainly delay their checks. My 50/50 claims were not disputed, so I am supposed to receive my first payment in December, but I will believe it when the checks are in my hand.