This is probably rubbish because different sources say different things (even people in the bike training school had different opinions)
You need to do one test to ride up a 125 with L plates (This is after CBT and could involve theory and more than one module)
Then another test to ride up to a 400 / 450? (Again could involve more than one module)
Then a final test to ride anything (same as the other two)
That's the basic template guess they are going to throw a theory test in somewhere could be just one or several it's a load of crap I don't think you will know for sure until it comes in.
If you can't get mod 2 before it all changes I would personally just wait saves getting a test done then getting it scrapped when the new system comes in and having to start again on something else