Yes, valid banking
The notice and the rent increase is valid
Your landlord is allowed to raise your rent once per
a year to account for Cost of Living. In Oakland, the way to find out the amount a landlord can raise the rent is through the CPI (Consumer Price Index). This changes every year. If the landlord decides to skip a year or more, they can stack the percent increase for those years into one rent increase. The limit for this is 10% in one year and 30% in 5 years.