The new criteria have been up on the site for almost a year now, and make it much more simple for a correct diagnosis to happen.
The proposal says autism isn't a learning difficulty and it isn't a speech/language difficulty. Those two other things are thought to be separate disabilities with their own category now.
Autism is extreme social clumsiness, an extreme need for routine/predictability/obsessions, and (usually) sensory processing differences. So they're focusing on those core things and working out how severe they are for that person.
If people had been diagnosed as having very mild social communication difficulties and very mild routine-needs, but great big learning difficulties and speech difficulties, yes, they might not get a diagnosis of autism any more. But they would get a diagnosis of learning disability, and a diagnosis of speech/language disorder instead. Then support would focus on those things rather than calling it "autism".
Likewise if someone can speak and has a normal IQ and has autistic traits which are mild that they no impact on every day living, they won't get a diagnosis either. To me, that seems fair, because the purpose of diagnosis is to make sure people have access to services. If they don't need any assistance with anything, compared to another ordinary person, the diagnosis doesn't have a point.
It does not mean that if someone can talk and has a high IQ for some tasks they will no longer be counted as autistic. It looks at whether they match the profile, and whether they have bits of life that are bloomin' difficult because of those traits.