my take would be that making a small edit and updating to follow latest guidelines are two orthogonal things and should be somehow treated like that.
I suspect that the official line of thinking diverges from yours.
The original question is essentially "grandfathered in" because you posted it before those rules went into effect. In other words, it didn't have to follow the rules when it was posted because they didn't exist, and we can't force people to follow the rules retroactively. Therefore, the existing rule-breaking question is allowed to remain because it didn't break the rules when it was first posted.
Here, and in other legal contexts, the grandfather clause no longer applies when you make significant edits/modifications. If one undertakes an edit on a question—no matter how "trivial" the edits—you will be required to bring it up to full compliance with the latest rules in the process.
Consider that the rules are there for a reason. It's not to punish non-native speakers or make it more difficult for you to post questions. They're intended to improve the overall quality of questions on the site, and on balance, they're working. We actively encourage people to follow these guidelines, and since you're editing anyway...now is as good a time as any to start following them.
Beyond all of those reasons, I also suspect that the verification code can't tell the difference between what you consider a trivial edit and a more substantial edit. And why should it be able to? An edit is an edit, and in fact, excessively trivial edits are generally discouraged:
Try to make the post substantively better when you edit, not just change a single character. Tiny, trivial edits are discouraged.
When you're going to edit, that's a good time to, well, edit.