The serial interface provided by Arduino can be utilized by many software packages that feature serial communication libraries. Are questions on setting up the serial connection, from such software with the Arduino, on-topic?
I would say no. Arduino really has nothing to do with it. It's all configuration in the 3rd party software to match the Arduino's configuration.
This may be on topic:
How do I configure my Arduino's serial port with the following settings?
This is not:
How do I configure this software to communicate with a device which uses the following serial configuration?
See how I said "device" instead of "Arduino"? Changing Arduino there doesn't change the question in any way.
I realized you may be referring to questions like How can I communicate Arduino to Matlab. Still, the underlying question is how to interface a serial device with MatLab, which really has nothing to do with Arduino specifically.
Even in that question, the first comment is
Do you need help writing the code for the Arduino, or help writing MATLAB code to read data input from the serial stream?