If you're concerned with balance initially, why wouldn't you rebalance?
The author of the article states that he rebalances out of crypto because of the growth rate.
Yep, sounds like he does. It's still possible that he would suggest someone getting started now not put in 10%, and that the reason he has so much is partly because of the historical growth. That is, he might have held onto this much partly due to the tax implications of selling appreciated assets. If he were starting fresh, he might not choose to put in this much.
> I try to keep Crypto around 10%
Seems like he's actively rebalancing it to ~10%
that's a good point, and seems very likely given recent history.