Moving is a stressful process for most businesses, adding onto that losing a lot of your data and confusing your Google Maps listing is something that gets added onto that.
But it seems like Google is trying to make that process easier. A few months ago, Google came out with guidelines on how to move your business on Google Maps.
Now I see that Jade Wang from Google said that in "most cases" Google is willing to move your reviews from your old listing to your new one.
Jade said in a Google Business Help thread:
We will transfer reviews from an old location of a business to a new location of business in many cases. We will not always transfer these reviews if the business goes through a significant rebrand.
I wonder if Jade can help me clean up my business's old listing from when I moved a year ago?
Forum discussion at Google Business Help.