Not really - cancellation being objectively as easy as signing up is still much harder to actually do for people with ADHD.

Signing up is something exciting and fun and something such person may do impulsively in a moment of weakness. Cancelling is boring and scary (what if dark patterns?) and a chore you don't look forward to, but rather try to not forget. It's not positively rewarding, but merely stops a penalty.

This might seem like an exaggerated difference, but it actually hits the exact points that are affected by executive dysfunction.