I downloaded the version from archive.org. Looks like it might say thank you on exit from the character converter. I just did a string search through all the files to find this though.
> Thank you for using the Wing Commander character converter
> Thank you for using the Secret Missions II character converter
Inside the zip, as well as loose files, there's what looks to be a CD image, containing this message. Perhaps part of the installer? Not sure why it refers to Wing Commander II either. It's next to a bunch of text about how you should upgrade to MS-DOS 5.00. This isn't part of any of the files.
> THANK YOU FOR BUYING WING COMMANDER II!
>
> Nearly ten man-years of work went into this product. Without the support of customers like yourself, we would be unable to continue to create games of this quality and scale. Please, do not distribute illegal copies of this software
Feels like I played a lot of DOS games though, looking back, so perhaps I got mixed up. Printing stuff on exit was not that unusual.