Does losing eligibility for the Disability Tax Credit affect how a Henson trust should be structured?

Not directly, because the Disability Tax Credit and ODSP eligibility are governed by different rules at different levels of government. The DTC is a federal income tax credit administered by the CRA, while ODSP is an Ontario program with its own separate eligibility criteria. A Henson trust's core protective feature, absolute trustee discretion so the beneficiary has no enforceable entitlement, is aimed specifically at ODSP's asset test, not at DTC status, so losing DTC eligibility doesn't, by itself, change whether the trust achieves its purpose for ODSP.

Where DTC status does matter more directly is for RDSP eligibility and certain other federal tax matters, which are separate planning questions from the Henson trust itself. If DTC eligibility has changed, it's worth revisiting your overall plan to make sure the RDSP piece and the Henson trust piece are both still doing what you intended, since they serve different purposes even though they're often used together for the same family member.

Because these programs intersect but aren't the same, it's worth reviewing your full plan periodically with a lawyer familiar with both federal tax rules and Ontario disability benefit planning, rather than assuming a change in one program automatically affects the other.