tengu_terminal_sidebar falls back to false, so showStatusInTerminalTab alone does nothing.
Showing session status in the terminal tab now needs both the tengu_terminal_sidebar gate and the showStatusInTerminalTab setting. The gate's built-in fallback is false, so with no server value the tab status stays off even if you turn the setting on.
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
tengu_terminal_sidebar Not enough to sayNothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.248: off
Read once, for one account on one subscription tier, against v2.1.248. It isn't a statement about your account. What a flag value here can and cannot tell you