There will most likely not be a difference in audio quality, but you will have more features. AV receivers have mostly been the same amplifier wise for the past 30 years, just with differing channel amounts and wattages.

But feature wise, they vastly improve even over a few years. A basic 5.1 or 7.1 modern receiver will have a bunch of 4k HDMI inputs, support for the latest surround formats, auto room correction, WiFi, Bluetooth, and further up the scale there’s Dolby Atmos much more.

So basically, a new receiver will sound the same as your current receiver, but you will get a lot more modern features with a new receiver.