This depends very much on the actual piano, and also on the acoustics of the room it is in. Opening the lid of an acoustic piano will reduce the muffling of high notes. There is usually some way to open the top of an upright piano, as well as a grand. Storing music books etc on top of a piano doesn't improve its sound quality!
If you were playing a Steinway model D or a similar "concert grand", it's unlikely you would feel there was any imbalance between the hands over that range, especially considering that Haydn's keyboard only extended for 2 1/2 octaves above middle C, which is a long way from the top note of a modern piano.
On a Yamaha grand designed and voiced for pop music rather than classical, you might find the right hand was louder than the left. (All models of Yamaha pianos tend to be "loud" in the treble in my experience, at least when they are new)
On a worn-out 50-year old cheap upright, you might well find what you described.
All of the above is talking about acoustic pianos. If your is digital, anything might happen, depending on quality the amplifiers and speakers or headphones, as well as on the piano itself.