The station will need a tug to bring it down

A dedicated deorbit vehicle is meant to put the ISS into the Pacific in a controlled way.

The station is far too massive to burn up predictably on its own. A purpose-built spacecraft is to dock and provide the final push, so that surviving debris lands in an uninhabited stretch of ocean.

The date keeps moving, but the engineering problem does not: an uncontrolled re-entry of a 400-tonne structure is not an acceptable option.