The most expensive cards in 151 feature several cards of the starter Pokemon and their evolutions, like this Squirtle on a beach
Identity Thief will become a noncreature Gideon with no loyalty, be removed from combat, and then be put into its owner's graveyard
The guide itself describes the conflict as ongoing, but Tezzeret notes that there is visibly a black hole in the center of the system, meaning that whoever supplied this outdated intel should be terminated
Apart from the issue of some cards not having playable substitutes, the other reason I tend to dislike this advice is that part of what makes formats like Commander fun is the diversity that they offer, and this diversity is built, in part, on players being able to access and play with weird, old, nostalgic cards that don't really see play in other formats
A longer quality assurance period gives you more protection in case there are any defects or issues with the products