I usually see mangas that have been in the yaoi industry for years or that blow up such as make me bark and mangawas simular to it. Another website that has a big audience is WEBTOON, WEBTOON is a website where anyone can publish there comics. And if the creators notice your art you can get featured, being featured is a goldmine for an author you get tons of attention and an audience up to 40.000+ people. There is a very popular WEBTOON and the name of it is “I love yoo”, it’s the number one comic on this website and it has an audience of 110,000+ people and is noticed by mangago and other big websites. So to answer your question, this website notices mangas that has a wide audience and they take it to their advantage and publish it on here. (To to come off harsh sorry)
MangaGo pirates these comics without permission. Authors don't usually want their works put up on here, since it takes away from the profit they'd get if fans went directly to the original sorce. So I don't think the author would really appreciate the offer. Don't know what kind of format the comic's available in, but you can share links if it's online with friends to spread the word. Social networking platforms exist for a reason. There are definitely better ways to publicize the author than ripping off their work.
I have a manga/comic that I just absolutely love!! The comic itself hasn't ended and can be slow to update but the story is great, to the point where I've reread, what there is to be reread, 5 times. It is because I love the comic so much that I wish to share it on here to all of the other hard core yaoi fans.(▰˘◡˘▰)