Immigrants who have filed I-485 petition residing in US and been waiting for more than 5 years should get a green card automatically irrespective of the visa wait times and priority date. The notion is clear that these people want to settle in US and there is no reason why the immigration department would hold these people from granting Green Card because of the decade old immigration process.
These people deserve to get the green card and please note that they followed the immigration guidelines as stated by USCIS. There is no system that favors the true expectations of the immigrants.