First off one would need to prove that Cannondale wanted everyone to believe that the team was using Lab 71 frames, and that "Lab 71" on the frame wasn't just an advertisement for Lab 71. Then you would have to explain why the info about the availability (or lack) of Lab 712 frames is such common knowledge if Cannondale indeed intended deception.
Then one would have to make the leap to understand that professional road racing is not just marketing, nor street riding, nor much in any way associated with what most of us do with our bikes. Since a lot of pro Tour bikes need (or used to need) ballast to meet the minimum requirement, while no street rider is in any way bound by UCI rules ..... yeah, not much point is giving the teams frames which are lighter and also need ballasting. But for a person who can build a bike as light as s/he wants for road riding .... the extra hundred grams might give you that psychological edge.
The tome of the OP seems to me to be sort of aggrieved at being deceived .... "Cannondale is Lying to us" because obviously if Lab 71 is "better" the team would use it, and if the team doesn't use it, it must not be "better" ..... but the key point there is the definition of "better."
Better for a UCI race bike and better for a road bike bound by no restrictions but the rider's budget and imagination are not necessarily related.
However, being offended is the new international sport of choice, it seems, and who am I to interfere in others' emotional athletic entertainment?