You are right you didnt say drop in replacement. It could be implied it would be easy though with this statement. "The 2.0T is a drop in solution with no headaches once it's mounted."
The warranty part could also be implied by the wording.
Once again, not keeping stock internals to make the same kind of power. If the internals put into the 1.8 are more than up to the task I see no reason it should not hold together. An extra 0.2L of displacement does not magically make it able to handle twice the power. The 1.8 left the factory with parts designed for 138 hp. Replacing those parts with ones designed for 300+ would allow it to survive just fine for a long time at sub 300 levels. They use large low RPM diesel engines due to the low end power they deliver. Completely different application all together and not even related to this discussion.
Once again, if the internals are replaced with stronger ones it wont be an issue if its driven in the same manner. For now though the 1.4s seem to be surviving with about the same failure rates as completely stock vehicles are.
Popcorn with salt and butter is delicious. Can I have some as well??