AMS vs AMS 2 Pro
Does not add new material types.
It changes how reliably you can print certain materials, especially in humid conditions.
AMS (original)
Stores filament
Enables multi colour printing
No active drying
AMS 2 Pro
Stores filament
Enables multi colour printing
Actively dries filament up to 65°C
The important nuance (this is the “Pro” difference)
AMS 2 Pro does not unlock new materials on paper.
It makes moisture sensitive materials actually usable day to day.
Examples
TPU prints more consistently
PVA dissolves more reliably
PETG behaves more predictably
ABS and ASA benefit indirectly from drier filament
So the upgrade is print consistency and reliability, not compatibility.