Unfortunately this pretty much makes every galaxy a ring galaxy.
I can understand the notion of the core being inhospitable to (humanoid) life due to the high star density and probably tons of radiation.
But that doesn't mean it should just be empty, ships should still be able to traverse it even if there's nothing worth colonizing.
Also it being inhospitable is mostly from an evolution point of view.
With advanced tech the core should be colonizable by already established races.
I can understand the notion of the core being inhospitable to (humanoid) life due to the high star density and probably tons of radiation.
But that doesn't mean it should just be empty, ships should still be able to traverse it even if there's nothing worth colonizing.
Also it being inhospitable is mostly from an evolution point of view.
With advanced tech the core should be colonizable by already established races.