You claimed that Rashi is saying something different on the Gemorah. He is not. He is saying the exact same thing. But instead of saying “Yaacov lo mes” he is saying “lo mes-he chai l’oilum” which is essentially the same thing.
If this is the only difference you saw in Rashi on Taanis then you have no idea what the entire discussion is about!
You clearly don’t even know what Rashi wrote in Taanis, and why Maharsha, Artscroll, et al understood him to mean literally.