Hmmm that page you point to shows the airfare classes you're eligible to earn/redeem. I don't see this table directly related/answering your question about eligible fare classes fulfiling the extension status.

FWIW, last week, I chatted with an AM agent to ask if a PEN-KUL-SIN one way redemption booking would fulfil extension eligibility. The answer I got from the agent was: YES, as PEN-KUL is considered 1 sector, while KUL-SIN is considered another, hence I've fulfilled the 2-sector eligibility rule.

Realize mine's a redemption booking while you're asking about a paid booking, but figured I'd share my experience if it helps Suggest calling CX's DM line to ask for a straight answer to your question (I'd love to know as well).