That is the article that Ivan also mentions in his video. I see 2 flaws in it:
1 - it assumes quantum entanglement is usable as a means for communication while there is tons of proof that that can not be done.
2 - it assumes that the blockchain itself is the vulnerable part. I strongly disagree here. It is exceedingly difficult to change the blockchain, even if you would have a working quantum computer. It is MUCH easier to generate a private key for an address from the rich list (yet today's computers are entirely inadequate to even attempt such a thing)