It's tax-advantaged in the sense that it allows for the trust to have access to graduated rates that are normally only available to individuals, or natural persons, whereas trusts are typically taxed on their top marginal rate. There would be an incentive, then, for a top-rate taxpayer to shift income to a registered disability savings plan to access the lower tax provided by the marginal rates, and to leave it in that plan to earn income subject to lower rates. Then at a later time they could use one of the schemes that the anti-avoidance rules are designed to prevent from extracting value from the registered disability savings plan to their own benefit, as opposed to paying it out to the benefit of the disabled beneficiary. That might be one example.
On November 2nd, 2017. See this statement in context.