If the offer is signed by all parties then it is enforceable. However there may be other ways to exit the contract. If the buyer tries to renegotiate the deal through inspections, there is no longer a meeting of the minds.... more
In my state, a foreclosure sale is several steps away from being evicted. After the sale the sale must be approved by the court. After the approval a redemption period must run. After the redemption period the new owner has rights to possession. Those rights must be asserted in a particular way. If you do not voluntarily depart the premises a legal action must take place to before the sheriff will visit with a request that the occupant leave.
There might be a PIRG (Public Interest Research Group) in your area with more specific details for Mass.... more