It's never offside in a million years (the question is why the linesman thought he could give it as interfering from his position? It must have been the easiest VAR correction ever) but I wouldn't have a problem if it was disallowed for impeding the keeper as long as all the other instances of impeding the keeper were also punished consistently. It's a pet hate (that and wrestling in the box, and mm offsides)
Who knows. Now we have scored one, maybe the guidelines will be tweaked again .......
It's another example of how poorly VAR is communicated, though. Who thought the VAR was asking the referee to overturn the on-field decision, and not just rule out the goal? Come on, be honest.