Zhao Jinmai was the spokesperson for Bai Xiaochun's milk brand, and they had collaborated to launch a new milk product called "Instant Milk." This milk product was designed to provide better nutritional companionship for Generation Z to meet the needs of young people. Bai Xiaochun's milk brand was committed to creating a more convenient and nutritious milk, in order to truly realize the concept of "using fresh milk to support you and cheer you up." Zhao Jinmai's energetic image was a perfect fit for Bai Xiaochun's milk brand philosophy, and it was something that was deeply ingrained in the hearts of the people. This time, the annual film that they had collaborated on had also led the trend of young people. Overall, Zhao Jinmai's partnership with Bai Xiaochun's milk brand was aimed at providing young people with better nutritional choices, so that they could stay energetic and healthy during their youth.
It could be Hagrid. He's always had a connection to strange and powerful things. Maybe he stumbles upon the knowledge of nen during one of his trips in the magical forest and then passes it on to Harry.
I don't think so. There haven't been any official announcements or indications that the HxH manga will continue. But you never know, maybe there'll be a surprise in the future.