(....)
But still, what is the possibility of the existence of metaverse without blockchain technologies?
This can be related to a digital currency that without blockchain technologies, is centralized indeed. It is controlled by a particular entity.
One of the most use of blockchain technologies is to make a decentralized application without any 3rd party entities, so if you can compare it with a metaverse that is controlled by a centralized entity. Then there is always a problem for sure.
But it still depends for me, because it will also depends on what is the use, what is the problem that needs to be solve and what is the goal of the project.