I would even take a bet and say that Neuer will still be playing in four years from now! I don't know whether he would still be the first goalkeeper at the next World Cup, but I do believe that he will still be an active professional goalkeeper.
I have to agree with you, as since 2019 I have seen news that Bayern would be looking for another goalkeeper to replace Neuer after his retirement, but that never happens. In fact news about Neuer's retirement dates back to 2016.
But, on the contrary... Neuer is still active and being one of the best goalkeepers in the world.
Regarding injuries, goalkeepers have a low risk for this, one more reason to believe that Neuer will continue for a few more years.
Neuer didn't have any serious injuries at all. If that was the case I would be rather inclined to say that it might soon be the end of his career, but if he can keep competing on the highest level possible with Bayern Munich, why would or should he stop playing?
The fact that he will be playing for the most important titles year after year also will keep him incredibly fit for another couple of years. It would really need a fundamental reason to not make him the number 1 anymore.
Flick is also counting on him. If he is playing in the German national team he will also be playing for Bayern. Can't see why that would change soon despite his age right now.