Maybe it's to keep the fans engaged and offer something fresh. The creators might have had new ideas or wanted to explore different aspects of the world they created.
There are quite a few famous magical girl characters. In the world of magical girl stories, Cure Black and Cure White from 'Futari wa Pretty Cure' are popular. They have a great dynamic as partners. Also, Madoka Kaname from 'Puella Magi Madoka Magica' is known for her self - sacrifice and the complex world she's in. And then there's Sakura Kinomoto from Cardcaptor Sakura, who is adored for her sweet nature and her journey to capture all the cards.
The reaction of site.com to manga can vary greatly. It could be highly supportive, promoting and featuring manga prominently. Or it could have a more limited engagement, only showcasing selected titles. It all depends on their business strategy and target audience.
I wouldn't recommend looking for unblocked manga sites as they often violate copyright laws and can be risky. It's better to use legal and authorized platforms to enjoy manga.