This summary is not the rule. The rule text controls.
When someone dies and their estate is being handled in court, the person in charge of that estate (called the succession representative) is the one who has the legal right to file lawsuits on behalf of the deceased person or their estate. This applies as long as the estate is still going through the administration process.
The heirs or the people named in the will do not need to be added as parties to the lawsuit. It doesn't matter if these heirs or legatees live in the state or somewhere else, and it doesn't matter what kind of case is being filed. The succession representative can handle the lawsuit on their own without pulling every heir into the case.
This rule makes things simpler for everyone involved. Instead of tracking down and adding every heir or beneficiary to a lawsuit, the court lets one person, the succession representative, act on behalf of the estate. This keeps legal matters moving faster and avoids unnecessary complications while the estate is still being settled.