"A June letter informing residents that police and K-9s would be accompanying housing inspectors didn’t inform residents they had a constitutional right to refuse entry to police without a search warrant. "

I don't think people should be depending on someone else to tell them what their Constitutional Rights are.  The Constitution text has always been readily available, more so in the internet age.  Even still you can obtain your own pocket guide for free
https://www.constitutionfacts.com/index.cfm?section=bookstore&page=freeCopy.cfm