So Marathon bought Hilltop Corp's lease position. They have no obligation to mineral owners to inform mineral owners of their intent to drill. They have to make sure that any location to drill has good title to make sure that their interest is protected when they drill and produce petroleum. This is a process. Secondly, Marathon has a drilling budget set up. They will get to your lease if they believe it in their best interest to drill there both geologically and to create production to hold the lease by production according to the terms of the lease.
Unfortunately they have no obligation to drill your lease unless there is a provision in the call a "drilling commitment". This commitment is usually located on an Addendum attached to the lease since the main body of most leases does not contain this provision.
If the lease is in marathon's plans to drill it, then marathon will file a drilling permit withe RRC and begin to build a drilling pad. this is evidence that they will drill a well soon, but not a certainty since drilling locations can be abandoned.