Does Wiping Data/Internal SD in TWRP Remove files Permanently? I am selling my Moto X Play and want to make sure all my personal files were permanently removed from the device. 

I did a Factory Reset from within the OS twice and noticed that my photos would still appear after the reset was completed. 

So then I booted into TWRP recovery mode and went to wipe and wiped the internal SD and Data on the device, booted back into the system and the pictures were all gone. I then flashed a completely different rom and pictures are still gone now. 

I just want to confirm that at this point that my files are completely erased and could never be recovered.
Of course. If you see the process of working twrp, you'll see that it erase sdcard without wiping data/media that is sdcard0, in some cases. It contains all of your saved files like music etc