I share that opinion so I'll answer. IMO, China letting control over currency just slip away is as realistic as China letting control over anything slip away. AFAIK it's still an authoritarian state. It could happen (it has a relatively free economy after all) but it's not consistent with China.
> Surely they don't see themselves as an authoritarian control-monger.
Why do you believe this? There's a very long chinese tradition of vesting control in the social hierarchy. "Authoritarian control-monger" may be dirty language in the US, but not everywhere.