I'm pretty sure the 2AP is materially different from the 1AP, however the rule 11 agreement had nothing to do with amended petitions, it had to do with the TCPA response. What Chupp believed the defense about was that the 2AP violated rule 63, which is that it was within 10 days of a trial and therefore a 'surprise' to the defense. The dispute is whether the TCPA hearing counts as a trial for the purposes of that rule or not. Ty and co say no, defendants say yes, Chupp is too lazy to investigate.
IMO part of the problem with it being a 'surprise', is that, aside from it not introducing anything particularly new to the case as a whole, I would think the 'surprise' is because the defense has no way to argue against it because they aren't prepared for it...but the defense shouldn't be arguing against anything in a TCPA hearing, because they don't really need to prove anything like that at this stage.