True. You need to know that and see if you can live with it for your use case. Some information is available at least, like the temperature coefficient of the pressure sensor [0]. Bosch offers an "interpretation library" that you also can train yourself specifically, that can be used for the successor BME688 [1]...
[0] https://community.bosch-sensortec.com/t5/Knowledge-base/BME2...
[1] https://github.com/BoschSensortec/BME68x-Sensor-API