Plenty, for example every iPhone before iPhone 4S with the exception of the original iPhone was announced at WWDC.
They haven't in over 10 years.
The Retina MacBook and Mac Pro (trash can and new grater) were announced at WWDC within the last 10 years.
Totally wrong. The current Mac Pro was announced at WWDC two years ago. Lots of other stuff was announced in 2017. The last Mac Pro was announced at WWDC in 2013.
The retina macbook pro was announced at WWDC in 2012.