Is the simple mention of Kenya, proof its a forgery?
Not according to this, one of the first few entries that popped up when I googled "Kenya Protectorate":
In 1920 the protectorate was united with the protectorate of Zanzibar, renamed Kenya, and made a crown colony, the coastal strip being known as the Kenya Protectorate.
I don't think it bothered the locals ~ they'd use whatever name worked.
Getting in "Kenya", and "Protectorate" and "East" and "Africa" seems quite reasonable. It's like Northern Virginia, DC Suburbs, Washington, etc. They can all mean the exact same place!