Nobody knows that. Nobody can know that. It's a new disease. You are talking about things that are highly speculative
Just because a disease is new doesn't mean we cannot observe how it is attacking the body in the present. And it's also not
that new, it is a new strain of a well known class of virus that has caused pandemic outbreaks in the past, so we have mountains of data on the long-term impacts of coronavirus type infections. This one won't be the same as those, but to suggest that it will be
less impactful when the initial stages are much
more severe is absurd.
If I shoot you in the leg with a new model of gun that has never been fired before, are the doctors who tend to you being "highly speculative" when they tell you that the risk of permanent disablement is high? Of course not. They may never have seen that bullet before, but they know, in general, what gunshot wounds look like. Legs don't magically heal themselves when shot by one type of bullet as opposed to another. You lose a tendon somehow, you're screwed for life whether it was an elephant gun or a zip gun. Similarly, anything that seriously impairs your nervous system in the way that a severe coronavirus infection does is permanent damage. You may recover some functionality, but it won't be all, the brain and spine simply aren't designed to magically rebuild themselves after certain kinds of injuries.