Thank you for your post.
There are two different ways to check depending on the file type you have. It also depends if you use a macOS machine or PC machine.
1. If you have a .ai document of your maps then you can right click on the document in a file explorer window > click on properties > click on the Details tab > and under Type it will show which version of Illustrator created the document.
2. If you have a PDF, TIFF, or some other raster format, you can check to see which version it was created in by using OSGeo4W. This is an open-source software that you can download with QGIS, or standalone. You can look up the GDAL info to see what produced the map.
1. If you have the raster format of your map, you can locate your map in Finder, in the information section, underneath the preview, you can show more information and it will show which version of Illustrator created the document.
Let me know if you are using a mac and I will look into it further to see how a Mac can identify which version of Illustrator created the document.