Bluetooth 5.0 and 4.0 changes
The simple answer is "no".

Bluetooth is a two-way communication, so in order to see any improvement from new features both ends of the link will need to be upgraded. There's no point in one end sending at higher power to get better range if the other end can't do the same.

It may be that the newer 5.0 chips implement the features of 4.0 a bit better, but you'll still be limited by what the other end can support. It's unlikely that a wireless headset will see any improvement in quality from the speed of 5.0 as 4.0 runs easily fast enough anyway, but obviously the enhanced range of 5.0 could be useful.