Nearly a decade ago, there was a website called thehunt.com that basically ran out of money and some employees were acqui-hired by pinterest.
All of the assets were left to rot and at the time the company was a good match for another startup of mine. So I reached out to the investors I found on crunchbase and asked if I could acquire everything. We worked out a deal and I did. The issue was the complete lack of people from the old company willing to assist and the complete lack of data for alot of things. There was 1 or 2 people who we could ping from the old company to ping who were super helpful, but the big thing was many things were just lost to time- passwords, history, code repos, etc..
Simply creating a new google apps account allowed us to get full access back to everything - We could even read old slack messages (even DMs!) by resetting each accounts password. The whole thing was shocking to say the least, but with that access we got back into literally every service they used and managed to get it up and running again within a week, which was a good thing because nearly every service it was using was threatening to shut it down every day for lack of payment.
I think the solution here is actually way simpler than most make it out to be and could easily be a startup for someone:
Create a startup that lets customers simply enter in domains. If the domain EVER goes into the "pendingDelete" status, inform the customer. The customer would be random SAAS's that want to protect against this type of attack and could simply choose to disallow access to any account that has had their domain go into that status.