
Is there going to be something between Juliette and Sigurd? Ik they're not blood-related but they were raised as siblings so I'm just wondering if that's where their story is heading.

I think the more accurate term would be pseudo-incest, which is still incest. Both Juliette and Sigurd thought they were actual blood related siblings still, so it's nothing like childhood best friends in the sense that there wasn't that distinction (i.e. them knowing and acknowledging the fact that they weren't actual siblings/belonged to different families).
There's a separate section for them in other mangas, so it's definitely an option for uploaders. You are going to make things difficult for future readers if/when these chapters get translated. Not at all saying the upload isn't appreciated, just please put them in the proper place on the website.