Its a reasonable question: a lot of these articles (which I dont necessarily disagree with otherwise) uses phrases like this one does:

"raised a record $144M" and "raising 9-digits cash"

Which isn't true. They raised 0 USD, and selling whatever the equivalent of ETH they did raise would likely crash the value significantly, such that they'd never see $100M+.

If they sold slowly, and if ETH value stayed relatively stable during that time, and if the exchanges were reliable for large, frequent withdrawls, and if all of this didn't raise huge red flags with the banks and governments in their jurisdictions, there might be something to it. That's a lot of ifs.

They raised about 3 million in USD and 2 million or so in Euro. So, there is cash involved, but most is BTC ETH LTC.

And if people do not start questioning why they have to keep dumping eth for cash continously until emptied.

Another question: how can they even "cash out" from the legal standpoint? Surely tax authorities will be interested in those millions of dollars "out of nowhere". It's possible to "stay under the radar" with small sums (e.g. buying your groceries with "BTC credit card"), but surely not with millions, right?

Just pay taxes on it like any business. Hire a CPA and CFO.