I think Jumong moved on after he married Yesoya. He also accepted Sosuhno's marriage to Wootae after she told him to forget about her. Sosuhno helped Jumong tremendously, but Yesoya deserves some credit too--she was willing to die for him.
I like SoSeoNo but I always wanted Ye SoYa & Jumong to be together. I know a lot of fans don't like her & I think she's misunderstood. But she is a lovely character, she reminds me so much of Lady Yuhwa with her spirit of sacrifice.
so now we know that Yuri is alive and well,
we know that Yuri is just like his father an exceptional human being and highly skilled fighter just like his father , hopefully they will protect him properly this time