Well that is exactly what the hearing, with its thousands (or possibly millions) of documents, is there to decide.
The emails are not bollocks, though. They clearly provide a basis for investigation (indeed CAS said as much). However, proving that (a) the emails mean what the PL/City's accusers say they mean, and even if they do, that (b) the arrangements were actually implemented, is another matter entirely. Not least because if proven, you are looking at a multi party conspiracy across many years.
That was always going to be near impossible to prove at CAS, with only a few emails in evidence in a two/three day hearing. In this hearing however, over two or three months, with millions of documents and ample chance to cross examine witnesses, it will be entirely possible IF the evidence supports the charges.
In short, we on the outside simply don't know if City have done something wrong, or (if there is some doubt about that) which way the evidence points.
The club seem confident. That is good. I wouldn't be too dismissive of what the emails say, though. They are concerning.