You need to reach out to the housing authority, not the tenant.

Many taxing authorities are wise to this, and so require some form of disclosure on the sale price of the holding entity.  

The inspector told me there is a new smoke detector requirement for Section 8 homes coming January 1:https://www.congress.gov/bill/117th-congress/house-bill/7981...https://www.us-hc.com/blogs/new-smoke-detector-requirement-f...Has anyone heard of this? 

It is a GREAT video on MTR with Jesse Vasquez (he has an episode here on BP) one of the leading MTR authorities.

Contact local authorities, consider long-term rentals (LTRs), work with a local realtor, and network with other investors to ensure the property fits your long-term goals.Good luck!

Do buyers have the legal authority to give the tenants 30 days notice to move out immediately upon the deal closing if they don't want to continue having them as tenants?

Author is Avery Carl with The Short Term Shop.  

I recommend focusing on getting a great investment property and disregarding Section 8 in that pursuit because any property can be a Section 8 property, but a lousy investment is lousy regardless of having a Section 8 tenant or not.Section 8 will perform a basic functional and safety inspection for your units after you have an agreement with a Section 8 tenant and your local housing authority.

Didn't the authorities notify of the sale? 

When we felt uncomfortable with this, and asked them to process a section 8 prospective tenant, they say they wont work with section 8 applicants because housing authority will pay the rent directly to the owner.