Does DJI Matrice 400 battery support self-heating functionality?

Yes.

When using the battery with the battery station: If the temperature of the TB100/TB100C battery is below 5°C, insert the battery into the battery station and turn on the power. The battery will automatically begin to heat. Once the battery temperature exceeds 20°C, self-heating will stop and charging will start.

When using the battery with the aircraft: If the battery temperature is below 20°C, insert the battery into the aircraft. The battery will automatically heat up to 20°C, then stop heating and enter a temperature maintenance mode.