As long as the house is still listed the sellers disclosures are good but that does not relieve you of your right and duty to have an inspection on the property. The seller will have to resign the disclosures at closing verifying that nothing has changed since the original disclosures were signed.
The buyer like the seller has to sign the disclosures twice. Supposedly when submitting the offer and second at closing after the seller has signed them.
McCOLLY Real Estate
State laws vary, so rely the most on an answer from an agent in OR. In my experience, as long as there is nothing new to disclose, the date they were signed shouldn't matter. If since they prepared them the roof leaked, or a pipe burst they would need to either rewrite the disclosure or amend it to inform you of what you need to know.
My concern regarding your question is why they waited so long to get you a disclosure form they obviously had since before they accepted your offer. The delivery of the disclosure being so late, may allow you options regarding the rest of the contract you may want to explore. Speak to your agent about this. In Washington, if a disclosure is not provided within 10 days, the buyer may walk away from the deal without consequences. In other words, they can quit at the last minute and still get their earnest money. Things may be different in OR, so please consult your local agents or an attorney.