[Super] [Spoilers] So did Toei/Toriyama change the time travel rules?

It seems like that line that Zamasu had at the end, something about fulfilling his promise of killing Goku, leads me to believe that that is the same Zamasu that the gang went and saw in the present. Personally I like the way the old time travel works so I'm not a fan of this. Did I miss something, or is it pretty much confirmed?

Edit: It seems likely that if that was current Zamasu from ep. 56 that he used one of the green time rings to travel to the Future Trunks timeline from his/Goku's. That makes enough sense. Also u/Cipher_- copied a very thorough comment from another thread here which explains a possibility well