When news articles mention the maximum, especially in headlines, it feels a bit misleading. It seems there's a decent chance there is little or no prison.
True.
> no one is going to plea to the maximum, which in this case is 20 years.
Unlike in some state systems, federal plea deals do not usually packaged with a sentence. You can plea to a more limited set of charges than initially charged with (or than the Feds were waiving around at you), but you usually don’t “plea to” a particular sentence within the range for the charge you plea guilty to. [0]
The reason the maximum sentence is what is in news articles is that it is a fact. Anything else as to what the sentence will be is speculation, but that the statutory maximum for the charged offenses is the upper limit is an uncontroversial legal boundary.
[0] revised from stronger language, a reply on a separate subthread corrected that; it is possible for federal plea agreements to include a binding sentence terms which the court can only reject by also rejecting the plea agreement. But very often they do not, and the reporting of the statutoriy maximum is in that case correct as the only knowable limit.
If that is the entire content of the article and it has no context to which it is addressed, I think its pointless, but, no, I see no reason in your hypothetical or any obvious extension to see it as disingenuous.
I also don’t see it as particularly usefully analogous to the situation previously being discussed.