I've heard the same argument made about other games, such as poker. "People get into poker because they get bored of their trading card games".
I'm sure some people do make the transition from one card 'game' to another (although I do not consider tarot a 'game' really), and this can be a love of pokemon cards or a love of bridge, transformed into a love of tarot.
I personally never played any TCGs before tarot. I did collect pokemon cards when I was really little, but that's becuase it was the 'cool' thing to do. Also, they were cute
Everyone has their reasons for coming to pick up a set of tarot cards and try reading them, and I suspect that the percentage who transitioned from the games you mentioned to tarot is no bigger than the percentage who, for example, had a deck passed onto them from their grandmother or aunt.
...That said, if you are looking at a certain age group - teens and children, only...I would say this article is probably true. BUT you might not like my reason for saying so:
Most teens/children are not likely to get into tarot, at least until later in life, because they are afraid of what their friends/family will think. It isn't cool or 'normal' to be into the occult, and a lot of teens/children are a bit too concerned with not doing anything 'abnormal'.
However...the kids who play TCGs, if you will forgive me for saying so, are usually not in the 'normal' crowd(s) at school. They are the same kids that are seen playing D&D, mmorpgs, and reading scifi books while walking down the halls. They are, usually, the kids on the outskirts, those who others refer to as 'weird', 'dorky', 'quirky' or some variation of this theme. Because everyone has already decided they are not 'cool', they probably feel more free to explore 'weird' and 'uncool' things, such as tarot cards.
Furthermore, people who are into these TCGs are probably more likely than the average person to have an interest in that which is seen as magical...because, well, the card games revolve around special powers and whatnot, don't they?
Anyway, I'm sorry, I realize I've made some sweeping generalizations here, and said some things that might offend, so I'm very sorry if I did, as that was not my intent.
Other than that, I can't say much on the similarities between tarot and TCG cards, except, maybe, you learn to look at pictures in corrospondance with specific cards, their meanings, the powers involved, etc...skills also used in tarot. As I have never played any TCGs, I can't go much deeper than that.