Meal replacement shakes like Huel would be considered “ultra processed” because they contain various industrially produced ingredients (artificial sweeteners, gums, extracts etc).
The evidence seems to suggest that less processed are healthier, particularly when it comes to these ultra-processed items, not just boiling/frying/cutting etc.
Personally I see these meal shakes being marketed as healthy/for athletes and think of how everyone 50 years ago though margarine was so much healthier than butter.