No. Officially, if you do not board the train at the boarding point, the TTE can allot the berth to any one. But conventionally, the TTEs wait for the next station only. If the passenger does not turn out there also, the nertj/seat is allotted to others. This convention is also followed if the next station is at a short distance of about 1 hour travel time only. It is better to get the boarding point changed. It woun't take much time. You have to carry a written request, copy of your e ticket and id proof. Meet the reservation supervisor, get his endorsement on the application, present it to the counter and will be done in few minutes.