I can't tell whether your suggested edit is correct. I don't know the subject, so I have no idea why
OneToOneField might be more appropriate than
ForeignKey. Tip: in your edit summary, don't just say “seems more appropriate”: explain why. Keep in mind that the people who review suggested edits may not be familiar with the topic. In principle, when reviewers are unable to tell whether a suggested edit is correct, they should skip it, but it saves effort if you don't force 90% of the reviewers into either making an uninformed determination or skipping the review.
Jon7's remark that “allowing random members to change answers defeats the purpose on allowing the community to vote on them” is incorrect and goes fundamentally against the core tenets of Stack Exchange. It is a core value of Stack Overflow and Stack Exchange that posts can be edited, and suggested edits were introduced to make this facility available to everyone while retaining some oversight to avoid abuse. Allowing random members to change answers is absolutely fundamental.
The rules for editing clearly state that
Common reasons for edits include: (…)
- To clarify the meaning of the post (without changing that meaning)
- To correct minor mistakes or add updates as the post ages
So if the use of
ForeignKey was a mistake, then you were definitely correct to fix it. This doesn't “change the meaning” of the post except in the literal sense that any edit, be it fixing a spelling mistake, “changes the meaning”. The rules that appear when you suggest in edit put it this way: “always respect the original author”. Is this something that the author would have written if he'd had the time to spend on it or if he'd known something that you do but he didn't? If so, go ahead and edit. If not, write another answer.