I'm not a developer-- not on OBS or on anything else-- so I am not qualified to say so either by specific or general knowledge.
If, as a layperson and a Mac user, I had to guess, I would say no, unless either Apple makes a positive effort to enable it, or the OBS project makes a considerable investment of effort to enable a method of capture compatible with Metal; and in all likelihood it would not actually come to pass unless both these things happen.
This is unfortunately one of the results of Apple abandoning an open standard (OpenGL) and replacing it with their own proprietary API.
I wish there was better news forthcoming, either from Apple or OBS, but in the absence of new information or announcements, I do think that users who need to use OBS and have Syphon functionality should remain with High Sierra.