Yes apparently they are coming back so here will be a lot of relieved users if this is true, check out the link....
https://www.phonearena.com/news/Galaxy-users-Samsung-has-listened-will-bring-back-customized-text-message-ringtones_id105781
Please be aware, this is ONLY for Samsung users (Oreo is not limited to Samsung users). The feature is being added to Samsung's Messenger app much as it's already in Hangouts (which I am using on my Pixel 2 XL as I have Fi for my cell plan and I CAN) but other devices will still not have this feature.
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