It is not like a magazine from 1994 is now changed because of a new understanding of a topic. As for books, the electronic version corresponds to the latest paper version. As for magazines, there have been a couple of changes, but in those instances, they were typos that were detected early and so the translated issues already had the changes (because they back in the old days were issued four-five months after the US originals).
If they really had wanted to change old versions, then why do you still find in the Ezechiel commentary book in the elctronic version that the prwaching work will be completed before the end of the 20th century? So changes are only made where there are changed printed versions.