Subleased room in San Francisco

[Paul K.]

My friend is the master tenant in a 3 bedroom 1 bath rental in San Francisco. They recently subleased out the room for a 6 month period and then Month to Month. In the lease, they put down that the tenant waives their right to be the only one to put in the 30 day notice(section 37.9), and that they, the master tenant, can put in their 30 days after the 6 month initial agreement.  In the lease, it is not as clear but states "the master tenant informs the tenant in writing that tenancy is not subject to the just case provision of section 37.9. 

  The 6 month period is closing in and the tenant is saying he will stay until "he" decides to leave.  He is unaware of the section 37.9 that is giving master tenant 30day notice. 

My friend isn't planning on moving back in yet, but is planning to in the next 2-3 months. 

My question is- should they highlight the lease terms to the tenant now or wait till they decide to give the 30 day notice? 

They don't want to have a disgruntled tenant in their home longer than they should.

Thank you in advance for any insight, and i understand this is a very San Francisco question!