I think you are correct here. I also think the sentencing is not a foregone conclusion yet. The judge must accept the plea bargain before the sentencing. If the bargain falls through the judge may direct that a trial be held. In such a case, the prosecutor may drop the charges "in the interests of justice". It would look bad for the prosecution but not as bad as if a sentencing occurred, exculpatory evidence appeared and it was shown that the prosecution knew about it all the time.
There is definitely a major problem with the Flynn prosecution and it is most likely centered around McCabe and possibly Sally Yates.
Lest we forget, the person in charge of the Flynn case for the FBI was McCabe who is by all accounts facing indictment himself. Yates was in charge for DOJ. The OIG has been focusing on this and the report is coming out soon. In fact, I would not be surprised if the Judge already has an idea of what it will say.
I went on record long ago saying that I thought the case against Flynn would have to be dismissed because if even 1/10th of what has been alleged by reputable media sources (forget the conspiracy stuff) is true, he was targeted and railroaded.