That means ST still manufactures it for existing production programs, but it is not the target for new socket designs. For existing builds, the NRND flag means you have a limited procurement window before the last-time-buy notice arrives; secure your lifetime needs now.
16 MHz, 8 KB Flash, 20-TSSOP — what fits
The 16 MHz core speed is enough for LIN-bus communication loops, PWM generation at a few kHz, and periodic ADC sampling — think window-lift controllers, HVAC flap actuators, or seat-position sensors. The 8 KB Flash and 640-byte EEPROM limit firmware complexity: you get one moderate control loop plus a calibration table. The 20-TSSOP package with 16 I/O lines gives you a handful of sensor inputs and actuator outputs, but not much room for a parallel bus or many external interrupts.