It’s likely because the Spousal OWP is still considered a pilot scheme so the information is not updated to reflect Spousal OWP applicants. This is why many people forget to pay the additional $100 OWP holder’s fee as it’s not mentioned anywhere else.
If you are required to give biometrics for your OWP (it is very unlikely) you'll be notified by letter/email.
Looking at the other applicants who are receiving OWPs via Spousal (the July folk) I’m not seeing any mentioning having to do biometrics so it looks like it’s just a case of CIV not updating the info considering the pilot project