Currently Aaron is still busy performing in many different areas for many opening ceremony/new years/ and other charity events. He will also be working on his movie, so for the time being he will be too busy to go to the practices for Tiny Times, but he is still wanting to take apart of it.
As of right now, Tiny Times has not stated anything clear about Aaron- and many fans are upset to see that the first performance does not have Aaron Yan due to many of his fans already buying tickets but the Tiny Times management did speak up that if fans wish to refund they will do so (hopefully they do not have to go through all that trouble though, I believe the musical itself will be very interesting).
Aaron Yan just recently returned from his mysterious trip to the United States, and was flown instantly to BeiJing for a performance there- so I believe his schedule is pretty much all plane time now. He himself said that the airport is now like his second home (FB), but he is enjoying all his work thanks to his parents giving him such strong work ethics to live by.
So for the time being, "Tiny Times" is underway and his movie's character has be exposed but no further details have been released, when they are I will do my best to update.