I think the majority of people were given a phone call to be told they were successful, which was a nice touch!
For those that got rejected, I feel for you. Rejection is part of life though, how you respond to it is something you can bring up in future selections. Being rejected and bouncing back shows determination to be a pilot. The two guys I met at Gatwick for my medical had been rejected twice for the FPP, but had succeeded on their final attempt.
For those that failed on the compass tests, I found sharpening up on Maths and physics helped me for those sections. Studying for the ppl exams also helps as you learn aviation physics, which is what the test is based on.
For those that failed on the interview. In my view the most important part of the interview is showing you have the motivation to train to be a pilot and the motivation to work for the company. Demonstrating both of these with real examples will help. Ie getting to solo in a piston plane or glider shows this isn't a flash in the pan. Have rock solid competency answers for teamwork, leadership, communication and motivation helps too..
In my experience the group exercises can be a lottery, but bringing people into the conversation (though not as blatantly as calling them out by name!) , listening, summarising and making sure the objective is achieved are all important.
Good luck, the preparation for your next selection starts today!