Does Meyer hatchery have a reputation for selling sick birds??????? I don't know. But I would think they do everything in their power to provide you with healthy birds. Otherwise they would be closing their doors quick. One week quarantine would be sufficient in my thinking. Myself personally, I would not quarantine them at all. I'm not afraid of my shadow. I don't have large flock to be concerned about. I like living on the edge and I feel lucky. In 18 years I only had 1 issue. I know that many peeps do things by the book, They would gladly beat me up for making such suggestions as not quarantine. You have to make the common sense judgment. If you are not sure of source, than play it safe.
I know that the avian flu is scaring the daylights out of many. The 47 million chickens culled due to it is real. Many chicken farms suffered huge losses.
I think Meyer is a top hatchery. I've never heard of any of the large hatcheries (in the USA) selling sick birds, but that doesn't mean it doesn't happen. I do want to wait at least a week just to make sure they have recovered from the shipping.
True bio quarantine is difficult to do for most BYCer's.
Keep in mind that your chickens could be carrying something that could affect the new birds too.
What were they vaccinated for?
Here's some links about quarantine and integration...take what you think helps and ignore the rest.