Your question is a good one. However, you seem to ask if appraisers are downgrading and yet your example was an upgrade.
To put it mildly, yes, appraisers have been shooting lower. They really took a beating for estimating higher property prices in the market run up. So now they are much more conservative. This can help buyers. I had one property where we went to escrow at about 500k but the appraisal came in at 485k. So my clients signed an addendum that said the bank will only loan on that value. The sellers dropped their price and my clients saved 15k. Some listings now try to take the appraisal out of the contingencies to prevent that from happening.
But it is not the appraisers fault. They have a lot of pressure from regulators.
If you need help, please give me a call or send me an email.