In my guess, due to all of his friends and family not believing him, and that his own eyes seems to having a habit of tricking him. Boruto's going to disregard everything as his own imagination and finally forget about it.
The Dark creature seems to be the villain that controlled The Kote guy, the victims of the creature were acting the same way The Kote guy acted as finally understanding that he was being controlled. In my guess the creature's going to lay low until Boruto the movie, and Boruto probably gonna disregard this thing as his imagination as well.
Boruto's eye though, seems to be a mixture of Byakugan and Tenseigan at my guess. Since the Tenseigan seems to be the the rinnegan of the Byakugan. As in the Tenseigan seems to lack the visual prowress of the Byakugan and instead have insane abilities just like the Rinnegen losing the visual ability of the Sharingan.
The only person who retained both in one eye is Boruto's very own Sensei who Boruto dreams of becoming just like him.
So Boruto's eyes seems to be just like Sasuke's case. A Tenseigan with Byakugan visual powers within it. I take that since Hinata seemed to have Hamura's chakra in her, thus her eldest child gaining the chakra and it mixing through his Byakugan genes and thus gain a newer dojutsu. And remember Hagoromo's chakra is what gave Sasuke his special Rinnegen so it seems pretty easy to say that Boruto's eye is a combination of his own Byakugan and Hamura's Six paths chakra.