Plea bargains don't count because they give up the right to appellate review of the constitutionality of the original charges, which would be very dubious after the Ashcroft precedent.
Resolves YES if the wikipedia page here:
https://en.wikipedia.org/wiki/Legal_status_of_fictional_pornography_depicting_minors#United_States
references such a case at resolution time.
I don’t think this is quite operationalizing “this question will be legally tested and it will be found constitutional to ban it”.
For one, it’s not necessarily the case that a plea bargain precludes a constitutional challenge to a law. You could retain the right to challenge in the plea agreement. I think you have to explicitly give the right up to be unable to challenge the law.
It is reasonably possible perhaps likely that if the Supreme Court does revisit the issue it will be in this situation.
Alternatively what if this issue is litigated pre-trial, with an appeallate decision saying the law is constitutional, then, on losing the constitutional appeal, the defendant pleads?