How come yonex discontinued the armotec 300 badminton racket in 2008? they only have the 2007 version.?

Sometimes, especially sportswear, they review their product and find out if people like the quality as if the product isn't helping people to succeed in their game then it is useless to the sportsman. The equipment is only as good as the person who uses it, it won't have much effect, but if it is more a hindrance than a help then you have a major problem. That is why it was taken off the market. Probably a problem with the materials used in the frame of the racket as I know at the club I go to a lot of people have had the frame bend and one guy even snapped his racket from an overhead shot and I believe they were Yonex.