The legal status search informs you whether a certain trademark is still valid, whether the trademark has been transferred, whether opposition or cancellation proceedings are pending, whether a trademark still has grace period or whether the list of goods and services has been narrowed down or partially cancelled.
Thus you know whether you can use a foreign trademark for all or part of the protected goods and/ or services, whether you might be able to successfully contest the foreign trademark or whether you'd rather avoid to use it.