if you see a chapter with no uploader name beside it, it likely means it was auto-uploaded by a bot- one that scrapes content from other piracy sites and reuploads it to mgg. the bot might end up uploading a low-quality image or translation (mtl).

any chapter that doesn't have an uploader name is uploaded by a bot
I don't know how it works but I'm assuming the bot knows what chapters are on this site and automatically adds new chapters it pulls from other sites
People put placeholders because the earliest translated chapters tend to be MTL or shitty quality in general
the bot sees the chapter is uploaded and assumes there's no need to upload another one