Well, … you can define church in many ways. There is the "church" of all the true believers in Jesus. Then there is the organization charged with caring for and maintaining the resources and beliefs of the church.
"TW" is the leader of the organization of the church. And there is New Testament precedent for such leadership. When I say "TW" is leader, he is responsible for carrying out the decisions of the world wide body of the church as determined by their actions at the General Conference sessions. The fact that certain sub-groups of the church choose to rebel is something for "TW" to have to deal with. I have already posted statements from EGW regarding decisions of the General Conference and how they are to be carried out. (One of the difficulties with so many threads is how many times do you have to / should you say it?!)
However, many do not follow or believe EGW and or any of the early pioneers of the church. Many also would rather take over the church and remake it in their own image. I do not think that is going to happen.
With over 1000 denominations in this country, it is a pretty well established fact that anyone can make up their own new set of beliefs anytime they want. Why do they choose to foment rebellion in the SDA church which has been given a mission to undertake and complete? So, again, it would really behoove one to seriously consider the story of the rebellion of Korah in the Bible or the book Patriarchs & Prophets. (Spoiler alert: the earth ate him!)