Why does pixiv now have a new string of text attached to file names of downloaded images only for lol E and shouta content?

I was downloading some images from pixiv on my pc and noticed there is a new long string of text added to the default file names of the images featuring lol E and shouta content.

For example previously all images file names were named like [(artworkID)_p0.png] but now lol E and shouta content have file names like [(artworkID)-xxxxxxxxxxxxxxxxxxxxxxxxxxxx_p0.png]. All other content which don't feature these two tags don't have this new string of text attached to it and have the regular old name like [(artworkID)_p0.png]

I am wondering what could be the reason for this change. I am a little concerned and wanna know if anyone else has a some clue on what's going on...