2000 Acura TL transmission Noise

I’m the original owner of a 2000 Acura 3.2TL, after 296,000KM I finally had the original transmission rebuilt (WOW I know). The transmissions shifts great now, no more slipping or delayed shifting however there is an annoying whistle / whining noise when I accelerate, sounds like an airplane taking off. It goes away after reaching cruising speed. The tech said this is normal for Honda rebuilt transmissions, I feel they just don’t want to take it apart again, they are so busy, should I demand they fix it or just turn up the radio and live with it. They gave me a 1yr 20,000km warranty. I am wonder if its the transmission pump but the noise is not there at idle or even when I reach highway speeds.

Thanks,