I don't think this is shrinkflation. 100g is a very, very common size for food products as here in Europe foods must have health charts (kcalories, sugars, etc) as both total for the package and per 100g. If the package is 100g it makes that easier and they only need 1 chart, good for smaller products.
This is just a European company selling the same product they sell elsewhere in a region that uses a very stupid measurement system.