Modern English grammar books like English Grammar In Use, first published in 1985, for example, has four editions till now, I am wondering if there are any notable worthy examples of changes in modern English grammar rules that differ in these editions.
Note that this question is not about random examples on top of your head, its about documented changes in grammar rules in editions of grammar books authorities, like Cambridge, Oxford, Longman, etc. so that your examples given are quotable in references.
A quick possible example I can think of is the use of stative verbs in progressive tense, like I am loving it. Well accepted nowadays it may be, but if it wasn't yet documented in one of these grammar books editions, I can't accept that as an answer to this question. Another quick example may be the shift from I/They shall to I/They will, but again, need to be documented.
This question can be easily answered if you can provide a link to one of these grammar books authorities (not any highschool textbooks), which lists out the differences/updates in their editions. But so far I tried couldn't find any.
Feel free to provide just the name of the books and their editions that you knew contain such grammar rules differences and I can go look it up myself.
Differences between different publishers (e.g. Cambridge vs Oxford) is also acceptable.
Meaning, spelling differences are excluded. Same audience, no British vs America. And only modern English, no old English comparison please.