They didn't even read their own links. From the Wikipedia page they linked (emphasis mine) :
Inheritance has become more common among households, with 60% of surveyed households in 2022 having received, expecting to receive, or planning to leave inheritances. Wealthy individuals make up 1.5% of all households but constitute 42% of the expected transfers through 2045, approximately $35.8 trillion. The wealthiest 10% of households will give and receive the vast majority of the wealth, with the top 1% holding about as much wealth as the bottom 90%
First off, the background is based on surveys, not hard data of any type. Expecting an inheritance doesn't mean being guaranteed to receive one. Where's the actual data? Second, it's painfully clear that this "great wealth transfer" is going to miss the vast majority of us. How OP could've read this and interpreted it to mean that Gen Y/Millennials are somehow, as a cohort, supposed to become super wealthy? I have no idea.
Then their CNN link, from its very first paragraph (again, emphasis mine) :
However, over the next twenty years, Millennials are poised to inherit some $90 trillion of assets and become the richest generation in history – but only the ones who already come from affluent families, potentially deepening wealth inequality further.
It's just rich people doing rich people things. This inter-generational phrasing is propaganda to distract us from the real opposition, the ultra wealthy, who are holding all of us down regardless of our age.