I was able to get this fixed with concierge help. Sharing the findings as this may be helpful if submitting through the form:
We sent Aeroplan a request yesterday with the information you provided us, to investigate why your plan was inactivated.
We did get a positive response and you'll be able to enjoy your WIFI Plan till January 7th, 2026.
The problem was caused by your 2023 plan which had a 3 months extension and expired on January 5, 2025 and prevented you from activating your 2024 Plan.
Your December trips were still on you 2023 plan!
So it seems with the new system you can’t activate the new plan until the old one expires which is great for most people who maybe have an early or mid year expiring and lets them select their benefits early on without causing it to override the existing plan but in my case (and I suspect for a few others) creates a weird edge case that needs manual intervention.