There are many ways a company could organize themselves.
Delaware LLC at least has to reigster in your state as a foreign corporation to be able to do business.
Some other time Delaware LLC could just create a new LLC in a particular state as subsidiary. Sometimes it's not for liability isolation but for tax purposes.
I am not sure what is your concern. You buy a house you have title insurance. If you are buying a bank owned property and this bank is in Delaware, you thinking about suing the bank?
That's above my pay grade. I am not in the business law specialty.
