That a rider would be so dominant is suspicious, yes. But there's context to it; he and Roglic were head and shoulders favourites before the race, anyone who might have been a genuine opponent either didn't start, or crashed out of contention. Imagine the 2010 Tour if one of Andy/Contador had crashed out, or just look at 2014 Nibali riding with no Froome/Contador, or Delgado in 88 with Hinault retired, Lemond out of action and Roche injured.
Just for the record: Nibali, Contador, the shclecks... are not clean pages.
With Armstrong, even with him running supposedly the most sophisticated, omerta doping operation in the sport's history, there was still plumes of smoke emanating, there was a constant stream of hearsay from within the USPS/Disco/Astana camp. As has been said on here, so many dopers these days are caught, not by the testing, but by police, by investigations, by reporting.
first we need to consider that most of the people caught doping are the low level riders. Those who use dope to barely reach the bar of a subpar domestique for the second 50km.
Hearsay for Armstrong/Telecom/Liberty/ and others didn't come at the start, they came gradually.
It is true that the biggest impact for 'catching' Armstrong was him getting the record of Tour wins. If he stopped at 5 i don't think the french would have kept pushing and pushing like they did. I think most people agree that testing doesn't catch the dopers, because besides a few specific ones, they missed a few very obvious ones..
The police/investigations/reporting are only done if people see the need for it. Again if Armstrong didn't win a 6th tour things would be differently for him.
Remember the Puerto affair? where some famous soccer players/tennis players were supposedly involved as well? think only the cyclist were beaten in that. So again it requires the people who want to disclose it. (barely exist for other sports) and i think it is becoming less and less in cycling as well. I think the people in the sport want to protect the sport from falling of a cliff.
Also, don't forget, this is the team that 2 years ago provided their riders with an experimental sports drink that led to them all gaining 2-3kg during the Tour. I'm sure they can do some things well, but running a doping program, that is clearly way above what other teams with more resources can run, and keeping it quiet, is probably very, very hard.
I'm sorry i haven't heard of this story, but gaining weight in a 3 week effort is BS i think. A body can only process that many calories. The biggest struggle in a tour is for your body to replenish the nutrition. Heck why in the old days you needed to be a bit more bulky so you had some meat to carve from yourself. Being able to gain 2-3kg in a tour smells more like some form of shenanigans than anything else. (Sounds like an overdone recuperation potion made for Obelix & Asterix)
If there is something going on at UAE (and for every sign that it is, eg Pogi's form, there's a sign that it isn't eg Hirschi) then sooner or later info about it will start leaking to the public.
To be fair, even Us Postal had guys not performing better, or widely varying over the years. Telecom the same, and they were also on program. (just like many other teams).
Forms can have many causes. Over training, injury, excessive winter, bored, mentally unfit, .. and many other can cause a rider to perform less. doesn't necessarily have to do with doping