Alarcon and Laporte are very strange examples to point at when discussing Geraint Thomas. The transformation of Thomas was obviously not something anyone could easily have predicted, but in that context you need to compare him to riders with similar career paths, like McGee, Wiggins and Dennis who were all primarily track riders before getting better at climbing. Up until 2012, Thomas' focus was mainly on being as good a pursuiter as he could be, and when that career was over, his performances on climbs started picking up rather quickly. I haven't read his book or anything, so I don't know what he has said about it himself, but I'd imagine that seeing what Wiggins did would have been a major inspiration to see if he could do the same.
Bringing Laporte into this conversation is rather meaningless, considering he was for all intents and purposes a sprinter before he became stronger and more durable as his career progressed. And while Laporte has done well in shorter ITTs in smaller races, Thomas has been an ITT specialist since early in his career, and that has always been a better predictor for GC results than being a sprinter.
And as with
@pastronef, I have no need to believe in anything while watching this sport. But I don't think you can stuff any classics rider full of substances and he'll then win the Tour. Point is I don't see Thomas' evolution into a GC rider as something completely outrageous considering what has happened before. But I also won't claim to have predicted it in 2012.