Ukraine would have blown up the pipeline anyway. And the land pipelines would have been cut off to Germany by the Eastern Europeans. So no, the gas would not still be flowing with a high probability. That's so absurd.

If Germany had gone to war Ukraine would be split between Germany and Russia now and the pipeline would be running. It is absurd to think there was any possibility of Germany going to war on Russia's side, but the result of them doing so is far easier to predict.

Of course if they had done that other countries would likely object and so we can go on and on with what could have been (for starters the propaganda would be all different). There are no easy answers and we can never know what would have happened.