I wouldn’t necessarily call this a “new” policy. It’s just unfamiliar to a lot of people who haven’t seen what financing looks like during a down market.
They’ll all get around to doing this if the current trends for decline continue, and the reductions on LTV won’t be limited to 5%, either.
And yes, I think the availability and terms of financing will have a direct impact on pricing, particularly for those buyers who view home purchases in terms of payments rather than price.