dude they may indeed be reo’s. Many times brokers will post signs on REOs prior to listing them because they are waiting on the lender to give them the listing price. In some cases there may be signs out for a few WEEKS before the lender sends the listing agent the price. It is a way for the listing agent to get leads and generate interest while they sit and wait for the slowpoke lender to get off the shnied.
Also Redfin is no different then ANY other on line posting site for MLS listings such as Realtor, Zip, SD Lookup, etc… Like anyoen else they get the information from IDX and put thier wrapper around it.