Rizwan,
The assumption I had was based on this, In case of Age, or IELTS or French certificates, its not in your hand at all, You cannot stop your age from counting, and you cannot determine when your application will be reviewed to take up your Language tests just in time. But, in case of qualification you know you do not work in the related area, and you still have time 1 or two years of time before your application is opened, hence you can very well work in the occupation related to AOT, and its definitely in your hand. If you go to the interview without any AOT experience you cannot prove that you will work in the related occupation and it may look like you are gaining points only for your education and not for the experience you gain out of it, hence the Interviewer may neglect either the experience or the AOT points, this was my assumption.
But Bachar had clarified that the 5 years will be based on the time the application will be received, hence may not be a concern. Thanks Bachar