Issues such as this are becoming much more frequent, because of the extensive requirements necessary to successfully document a loan, since the 2008 mortgage
crises occurred, and the laws were changed to protect investors and borrowers from unscrupulous lender practices.
The real estate
industry hasn't caught up to the reality that meeting the same closing dates that were once routine, is now generally impossible.
So, the answer is "yes," the agents should be telling their clients that the lender is not likely to be able to perform in the time allotted -- and the lender should be legally liable when it agrees to fund a loan in a timely manner, but fails to do so.
Unfortunately, there are no statutes or regulations that impose any requirements such as I describe. They are all simply giant loopholes in the federal real estate settlement laws (collectively termed, RESPA
The seller's demand for additional compensation, if it is not expressly provided for in the contract, is unenforceable. And, if the seller cancels the deal, then that means the seller will have to find a new buyer. So, the seller really doesn't have much leverage here, if the buyer simply refuses to pay anything more than the contract price.
That said, if I were your son, I would tell the lender and my agent, that if I'm charged one penny more than the contract price for any of these delays, when everyone involved almost certainly knew in advance that the sale wouldn't close in time, that I will sue both agents and the lender, for breach of fiduciary, and I will complain to the real estate commission.
And, then I would kindly ask that everyone throw in some dough to assist the seller, because they are the ones who have created the crises.
Please let me know if I can be of further assistance.
Hope this helps.