This sounds like B.S from Waves.
I think they simply dont want to put the money / time to port all their plugins to AAX DSP.
Fine.
Just say it's an economic decision. This thing about the SSL channel is B.S.
HDX is more powerfull for all plugins exept the Waves one?
For me, when i'll make the switch to HDX, i will not miss Waves plugins.
The only one who see's a lot of use these days is Q-Clone, and it's not TDM anyway.
Cheers.