Read the headline. Apple misled iPod owners plaintiffs allege at trial. How does one mislead consumers? Marketing. Whether that be through communication, commercials, brochures, collateral, info on a box, etc.
It cracks me up that you can't seem to figure out everything involved potentially in this trial. Where in any article does it say the trial is about email? It doesn't yet we know they will use emails written in the trial.
While one form of misleading could be from marketing, there are other forms too and I didn't see anything in the article to show it was from marketing. Rather common sense would seem to be the reason people assumed their iTunes music would work on other MP3 players or their purchased mp3s from elsewhere would work on iPods. A misleading marketing example would have been explicitly showing or stating iTunes worked with other MP3 players or vice versa.
A main focus of the trial will be jobs' testimony which does include emails. (Per this macrumors article and your link)
From your link I would side heavily with apple. plaintiffs quotes as well as their reasons do not show me any merit they have been wronged from what (admittedly little) I understand/know from antitrust law. Further I also side with apple in their reasons for doing the software updates. Not having permission from apple to use iPods, then explicitly writing code that undermines apples own software so their own music services would work on iPods and thius profit off of it....then to claim Apple was in the wrong when Apple blocked their competition from using apples products and blocked third parties from profiting off of apples products is absurd. Both parties look silly saying 'it's for the customers best interest' I think iPod consumers would be more likely to yell at Apple if for some reason the third party music service crashed iPods. I thought this took place near the beginning of the 00's but maybe I could still see people were still used to buying physical CDs and thinking iTunes mp3s would work like having a cd and being able to play on different MP3 players. However it was so common to have electronics only work exclusively for one brand up until pretty recently plus I'm sure it was in the service agreement no one read.
Still, I don't see what Apple did was taking away the competition. apple had a majority share of MP3 players at the time but I don't draw the connections from that to other companies being limited to making their own MP3 players,or making their own music software/online music buying apps. The plaintiffs quote about the software update that crippled their music software not being big enough is laughable. Saying a software update should have made the device "cooler", "sleeker " and/or "smaller" to be a "genuine" update. One professor of pay me a little and I'll say anything is a witness who will testify iTunes "blew everything up" if put on a device that wasn't an iPod. Well duh, if it wasn't designed for that player why should a reasonable person expect it to work correctly? The plaintiffs go on as if Apple was the reason other companies were making inferior products or products not as popular.
It is interesting to have a discussion I think on how the purchasing of digital audio/video should be or should have been. Many people I know were frustrated with using iTunes as the only option of managing iPods. I'm also sure there were probably some great software/apps people could have done for the iPod which would have improved it for consumers but Apple made the iPod how they wanted. It's not against the law to not get everything we want out of a product. You take the good with the bad and we decided the iPod was good enough, cool enough, easy enough that it out weighted the bad.
Jesus, sorry I wrote so much