Let me be clear up front - it's apparent that George Michael did, in fact, have an estate plan of some kind. This article is not meant to insinuate that George failed to plan, but rather using his familial situation as a perfect example of why planning is so import to effectuate your wishes.
Unmarried, No Children
While George seemed to have a serious relationship at the time of his death, he was unmarried and passed without natural or adopted children. In the State of North Carolina, his father - his only living parent - would inherit his entire probate estate without an estate plan in place through the rules of Intestacy. If his father predeceased him, his two sisters would share equally in his estate. These are the state's default rules. Obviously this is purely academic as George lived in the UK and did, it appears, have a plan in place. Point being: the state's default rules are almost never the preferred method of asset succession for deceased individuals.
George's Godchildren, Boyfriend
There is much speculation (since his will has not be published as of yet) that George's godchildren will share in his estate by virtue of being included in his estate plan. George was very close with his godchildren up until he passed, so it would logically follow that in the absence of children of his own, he would include his godchildren in his estate. Many people include children not their own in their estate plans for a multitude of reasons. Likewise, it's common for unmarried couples - whether they be dating or unmarried life partners - to include each other in their estate plans. This process is an example of empowered planning - saying "no" to the default rules and creating your own rules through estate planning.
No Legal Relationship, No Inheritance Rights
If you're goal is to include people in your estate who have no legal relationship to you, you have to be proactive in your planning. In this case, in the absence of a plan, George's godchildren would not have an inheritance right in his estate through the default rules. Likewise, his boyfriend would be left out. Without proactively including these people in his plan, George's ultimate wishes would not be effectuated. Failing to plan is planning to fail.