grammar - How to properly refer to a person who had changed their name in the past tense?

A person changed her name from A to B.

"My 6th grade English teacher was A" sounds right, but when I alter the sentence structure to "B was my 6th grade English teacher" it sounds right. These are just 2 variations of the same sentence, so why does the order make referring to the person with a different name sound correct?

According to Past or present tense when talking about firsts that happened in the past?, one should always say "My 6th grade English teacher was..." and not "My 6th grade English teacher is..."

I think the "was" version requires using her old name, but the "is" version (although not grammatically correct) is 1 way to use her new name.

How to properly refer to a person who had changed their name in past tense?

Answer

‘My 6th grade teacher was A’ and ‘B was my 6th grade teacher’ are likely to be used in different contexts, and it is the the difference in contexts that explains why it is natural to use the old name in the former and the new name in the latter. ‘B was my 6th grade teacher’ presupposes a context that is anchored in the present, that is, it presupposes that those involved in the conversation know this person in the present, under the person’s current name ‘B’. The sentence begins by directing their attention to that person, and then proceeds to provide one tidbit about the person’s history. On the other hand, ‘My 6th grade teacher was A’ is entirely about the past; it is likely to be used when people are reminiscing about the time when they were in the 6th grade. In such a case, the old name, ‘A’ is a part of the content of their reminiscences, and the person’s present-day name is irrelevant.