You want to know something?? Okay I'm not really a big fan of anything Boruto and also SP but at least I always make myself to notice and remember something significant. Back to the point. Otsutsuki actually the brain child of SP and only Sage of Six Path is Kishimoto's idea. Before Otsutsuki came into the picture we only know Hagoromo as Sage of six Path, until Naruto met with him. The first time Otsutsuki came into the picture was when Edo Madara explain to Edo Hashirama about the history of Juubi/Shinju/Chakra fruit.
From there onwards we're being introduced to Hagoromo, Hamura, Indra, Ashura, Toneri, Momoshiki, Kinshiki, and Urashiki. You can see the trajectory/pattern there. Like I said earlier the idea of Otsutsuki coming from SP and not Kishi or his previous editors. So when Madara introduced Kaguya for the first time, SP starting at that point of time is on the driving sit. They're in control of anything related to Otsutsuki. Kishi just agreed and approving SP's ideas of Otsutsuki.
So for Urashiki his future lies in Boruto anime conducted by SP. And I believe more Otsutsuki will be introduce by SP in the future.
