It sounds like an issue with the manufacturing tolerance of the fan and the plastic mould surrounding the GPU
Is it a gigabyte card by chance?
They've had an issue with that before and it sounds like a pretty common problem
But nothing concerning as long as the temps are fine and the fans are able to ramp up
It would only be an issue if it's making that noise all the time which would indicate the bearings are going out
In that case it would be a problem because the cooling would be compromised when they eventually go out but that doesn't appear to be the case here
If you're especially concerned you could run a GPU stress test for peace of mind but I wouldn't worry about it personally