I guess if Takara-Tomy wanted to use the ideas anyone came up with, they would have to ask permission from the person first, and would probably have to mention them when the item based on the idea is released. It would be illegal for them NOT to do that, cuz you could probably consider it as some form of copyright infringement. It was your idea at the end of the day, not theirs, and they stole it from you.
But still, if we want our ideas noticed, the best thing to do would be to contact them. xD
But still, if we want our ideas noticed, the best thing to do would be to contact them. xD