That won't help if the cause is that their anti-aliasing filters are cutting too many high frequencies in their new Agoura circuit topologies - for example.
Problem is.... you change that, and you literally change everyone's presets, and everyone will complain because they're used to the way it sounds. Cliff experiences this all the time too. He improves something, and people get annoyed because their sounds changed.
This should've been caught by an alpha tester IMHO. But the problem you have is, lots of modelling people haven't used real amplifiers for decades at this point. They've forgotten what they're supposed to sound like.