Surviving only requires that there be enough people playing to fill a game - it doesn’t have to be popular or receive frequent updates. Technically, HoTS is still “surviving”. Even WC3 and SC1 are still “surviving”.
So yes, I see OW2 surviving well beyond 2025. The amount of support Bliz gives it, however, might be open to question.
Let me ask another question: At the moment I write this, Team Fortress 2 is still the #13 game on Steam for players playing the game, at 64,552 people playing right now. Do you think TF2 will at some point surpass OW2 for active players? If so, when?
(Source: https://steamdb.info/charts/)