Anything that has to compete with with twist of fate will seem bad... I really think that ToF should be baseline (maybe nerfed by 5-10%) because that playstyle of executing minions and keeping ToF buff is clearly super core to the current and future iteration of shadow. Give us some room to actually have real talent choices in that row while preserving the ToF playstyle. Buffing other talents is meh too, because either they are buffed so hard they become the default choice, or they're not buffed enough and ToF is still better. I guess you could make a similar statement about other strong talents, but ToF is basically strong in all situations so it doesn't really give room for niche talents to flourish around it.
Not even just for Legion, but in WoD it was the ONLY talent that I never switched. Every other talent row had at least 2 choices that were viable in different situations, or at least different patches. ToF was always the best choice for everything.
I don't have Legion access and haven't closely followed everything, so maybe there's only one good choice for most talents in Legion.... but I'd be surprised if it's as one sided as ToF always is.