In aggregate it has, but the processing and quality of the oil has certainly changed. Notwithstanding, there has been a steep increase in total consumption of vegetable oil since the mid 20th century, owing to boxed / processed products. It's possible that the primary issue is oil consumption is not as moderate as it was.
Yes, the fact that the Chinese have been using soybean oil for one thousand years may be completely irrelevant for the properties of the soybean oil produced today.
Until last century, the oil was produced by pressing.
Now it is produced by solvent extraction, which extracts much more oil, but it may also extract other substances, which were not extracted by pressing.
The research commented here has shown that not the actual fat from soybean oil causes problems, but another unidentified component.
It is quite possible that the dangerous soybean oil component is something that is present only in the modern soybean oil, obtained by solvent extraction.
