???? You do realize the source material is censored right???? It's Japan's law to have them censored. I assume we are talking about VNs from Japan here. If the source material has mosaics and the localization has mosaics it makes no difference here. Additionally, it's not always possible to get the non-mosaic CGs. I don't know if you know this but a lot of the time the artists making it know it has to be mosaics and thus don't actually draw the mosaic parts fully. Thus the "original non-mosaics" sometimes don't even exist even within the Japanese company.
Also you kinda contradicted yourself? All-ages has plenty of censorship in re-phrasing more lewd jokes, cutting some non-H CGs and changing other lines. For example ニュートンと林檎の樹.
Also, I'm not sure what VNs you've been reading but the first H-scenes are rarely at the end of the story.... They are very commonly during the middle of heroine routes or hell, again in ニュートンと林檎の樹's case or like noble works or plenty of Yuzusoft games though one can argue yuzusoft has no story xD have H scenes at the beginning of the routes.
The topic you are bringing up is a consensus shared by many here that we don't want censorship in our games. The thing is, mosaics are not a censorship by the new publishers. It's from the source. What that Reddit post and everyone else is concerned about is the that publishers will change the source material by censoring certain things and changing the source material. And again, since mosaics are already in the source, it's not a valid argument.
Edit: Basically we want to say to publishers "Hey, you see these lines in Japanese? Make them English and don't do anything else" And if it's originally mosaic and it's released mosaic then I don't see where this "censorship" you're talking about is at. You are essentially getting what the Japanese players got originally. Isn't that what you want? If you say hey I want you to unmosaic this then I get worried since they might think " hey since I'm changing something lets also change even more things" and that's where I get my pitchforks.