I agree that those are valid concerns. And yes, the new API will be more restrictive, it sounds, and intentionally so.
But the post asks for feedback and input regarding what new APIs to add. You're right they won't add everything, but we don't know yet how much they will. They also say their team is hiring more people to help move this API forward and work with addon developers to port their addons, so slow progress in the past might finally be changing now. This sounds like it has become a high priority.
So overall it's hard to say how much of a problem the issues you raised will be. This path has some obvious benefits as well as risks, and it'll be interesting to see how it works out. I just think wholesale pessimism at this point is unjustified.
But the post asks for feedback and input regarding what new APIs to add. You're right they won't add everything, but we don't know yet how much they will. They also say their team is hiring more people to help move this API forward and work with addon developers to port their addons, so slow progress in the past might finally be changing now. This sounds like it has become a high priority.
So overall it's hard to say how much of a problem the issues you raised will be. This path has some obvious benefits as well as risks, and it'll be interesting to see how it works out. I just think wholesale pessimism at this point is unjustified.