When blue flags appear on names and you click the flag a message comes up that "the record has been removed".
Sent the patron the link to the census. https://www.familysearch.org/search/catalog/1307314
This is what happens when the blue flag is opened.
Did you try to search from https://www.familysearch.org/ark:/61903/3:1:S3HY-6QLS-H3B?owc=waypoints&wc=MGDQ-Y4M%3A287604901%2C287604902%2C287604903&cc=1307314?
Obviously, we can't tell if this collection was indexed and the indexed records have been withdrawn, but it appears the images might still be available. You will need to know the exact location to help you narrow down an otherwise daunting task of finding this person in the 1930 Mexico census.
Another thought: maybe just records relating to certain areas have been withdrawn.
I don't know what happened with the pointer on that Record Hint/blue flag - but using Search> Records> by Collection> Mexico National Census 1930 - I find 3 results for 'David Alducin':
Each one is viewable.
Comment(s): It appears that some of the problems people are experiencing with Search may settle down over time - they may be doing some 'reorganizing' in the background that we are not seeing. Patience is needed!
It kind of makes sense that the 'new Search' rollout might 'break'/change some Record Hints that have been on Persons. Those will probably need to be 'refreshed'.