Illegal B.C. Landlord Tenancy Situation

[Vincent A.]

Who: Landlord Vs. Tenants (Close Relatives)

What: Landlord is looking to push out current tenants and instead increase rent by 25% by stating that their son & family are looking to move into the unit (which is allowed via B.C. Tenancy laws - https://www2.gov.bc.ca/gov/content/housing-tenancy/residential-tenancies/ending-a-tenancy/landlord-notice/two-month-notice)  

Where: Vancouver, B.C.

Situation: Some close relatives came to me with their situation where their landlord has given them "flexible" notice (as in no specific date) that their son & family are looking to move back home to the basement suite. Where things got fishy is when the landlord stated that their son would be paying "1500 in rent" and if my relatives could match the amount, then they could stay. This raises eyebrows. Current tenants have been there for 5+ years and have had 0 issues paying rent.

Their current rent is 1200 for a 2 bd/1 ba basement suite. Where surrounding areas are renting for 1400-1500. With B.C. Tenancy laws freezing rents during Covid until end 2021 and only allowing to increase rent (5% ish) once every 12 months - the landlord is definitely losing potential capital.

What could/would you do in both the Landlord and Tenant situations?