1. Someone decides that we need inventory of all the libraries used (iirc requirement for some certifications and generally not a bad practice)
2. A system (/excel sheet) is enrolled where you have fields like $our_product, $library_used, $vendor_email
3. A dev, not quite understanding the point, dutifully fills in the data for the project they are working on
4. No-one reviews the data
5. Crisis strikes, so mass-send email to all vendors how they are handling it
Problem here is around point 4.; for the process to work, someone should have reviewed the data to check that the used libraries are from vendors with some sort of support arrangement.
I think the reply they provided is pretty promising, it makes it sound like they wanted to be a customer but are not only due an oversight.