Google has posted a notice that the old customer reviews links in Local Service Ads will expire and the Google Business profile link will be what you should use going forward. The notice is in the reviews section within Local Service Ads.
The date they expired was July 8, 2024, which was in the past. But I just noticed this now and it was posted last night by Ben Fisher on X. Ben wrote, "News: LSA officially is stating to use your GBP review link and not the LSA review link."
Here is his screenshot that says, "Your old customer reviews link will expire by 2024-07-08 as we migrate review collection to Google Business profile. To collect reviews going forward please use your Google Business profile link which you find in the verification page."
As you know, LSA reviews had a lot of fake review issues with many bugs including reviews being hijacked. Google did add a way to report reviews after posting new LSA review requirements - but I guess consolidation is a better idea.
Update: Mike Blumenthal called this would happen months ago...
Forum discussion at X.