Like XenForo 1.x itself, add-ons for XF 1.x are in support mode. This means that they will receive bug fixes until May 31st, 2019 and security updates only until December 31st, 2019. They are feature locked and no new features will be added. As of December 31, 2019 they will be End of Life and no further updates will be given after that date.
I have many people uploading different file types and I got tired of the generic file icon in XF and I did this for myself after investigating another add-on that does the same thing. I didn't like the way it was being done and decided to do my own.