This happened with appliances. They ended up with the silly A++++ ratings added in 2010 as otherwise everything would be an A.

In 2021 they decided to redefine grades instead. A fridge at A+++ became a C. A became the top grade again.

It's also worth noting that as they push the whole scale and G into being more efficient that essentially bans products that can't achieve a rating.

if everything becomes an A the system has worked and increased the efficiency across the market. They'll adjust the goals every 5 to 10 years.

The EU battery life measure is going to be the most interesting battle ground in my opinion. "All day battery life" will have a measured metric in hours.

If the EU have managed to make that metric representative of an amount of screen time in a busy day it could become the first thing consumers look at. Or at least a deal breaker when that number is too low.