In my opinion, this is a flawed statement.
It boldly assumes that you need to be capable of thought to exist, assumes that you simply need to think to be real. But what is existence?
How to we really know if something exists or not? Is AI, that has true intelligence and the capability of thought, a being? Are the animals in the zoo capable of thought? Is the random bug, staring at you from the ceiling, capable of thought?
If fact... what is thought itself? What and how can we classify as a thought? What if we are a simulation, are we still an existing being? Or are we simply some code that isn't actually real?