The 2024 Platinum states the following and seems to be updated in terms of trip interruption but it seems like as long as it's a split payment with another card vs points? :
Coverage is only available if you are a resident of Canada while you are travelling outside your province or territory of permanent residence.
• For trip cancellation coverage, only the trip costs charged on the Cardmember’s Card will be considered for reimbursement, up to the benefit maximum. Any expenses incurred using other payment sources will not be considered.
• For trip interruption/trip delay coverage, benefits are payable to you as long as any portion of the trip costs are charged to the Cardmember’s Card, up to the benefit maximum.
Furthermore it states this:
Effective date - means the date and time any portion of the trip costs (before any cancellation penalties have been incurred) are first charged to the Card by the Cardmember, or paid by redeeming Membership RewardsŪ* points earned under the Membership Rewards Program provided any applicable taxes are charged to the Card. Note: Trips will not be covered for Trip Cancellation or Trip Interruption, if purchased with points from a reward program other than the Membership Rewards Program.
Trip - a period of travel outside your Canadian province or territory of residence for which: a) There is a departure point and a destination; and b) There are predetermined and recorded beginning and ending dates; and c) Any portion of the prepaid travel arrangements was charged to the Cardmember’s Card prior to your departure.
Note: For trip cancellation coverage, only the prepaid travel arrangements charged to the Cardmember’s Card will be considered for reimbursement, up to the benefit maximum. Any expenses incurred using other payment sources will not be considered.
For trip interruption/trip delay coverage, benefits are payable to you as long as any portion of the prepaid travel arrangements are charged to the Cardmember’s Card, up to the benefit maximum. This definition is extended to include a common carrier ticket or accommodations obtained through the redemption of points earned under the Membership Rewards Program