This is blatant, willful and permanently-documented tax evasion, an amusing combination of illegality and stupidity.
This is really no different than selling and buying stocks in an IRA account.
On 31 December 2017, the IRS clarified that § 1031 does not apply to crypt-crypto trades. It did not say § 1031 applied to crypto-crypto trades before then.
The article you reference says "traders still may be able to argue that their transactions undertaken in 2017 and prior years were not taxable under the Section 1031 like-kind exchange rules," but that "the application of the like-kind exchange rules to crypto transactions is far from certain" [1, emphasis mine].
You transacted into (what you believed was) a proxy for cash. That's obviously selling.
Every tax jurisdiction has rules about this because every tax jurisdiction has idiots who thought they'd found a clever workaround. (I think the first American one involved a guy in the 19th century selling property for the key to a lockbox full of cash.)
In reality if they want to punish you for this they'll see right through it. Loopholes are only loopholes because there's an established history of authorities not willing to enforce it (brown paper bags around liquor bottles, "Suggested Donations").
This is an insane assertion. One of the main points of an IRA is that the trades within it aren't taxable events. Trades made outside an IRA are taxable events.
But I see the point here regarding a cash proxy.
Full disclosure: I have zero exposure to crypto. Not my cup of tea.
Essentially, you're being taxed on the income you got from holding that security, not for trading, it's just assessed when you trade.