I just suggested this edit to this post and it was rejected by Community. I believe it was a good edit. I improved formatting and grammar.
What I edited:
Another user with full edit privileges made an edit to the post after you suggested your edit, but before it was approved.
In such cases, the suggested edit is rejected by the community user and the later edit is applied.
While your edit could have done more, I wouldn't go so far as to say it was bad, just less good than it could have been. Had there been no edit conflict, it's likely it would have been approved.
If you look at your edit suggestion more closely, you could have made 2 more "i" uppercase further down the question.
Especially so as that is exactly what you did further up the question.
The idea is, if you're going to edit, and especially when it needs approval, make sure you get everything you can in the first go, so it's a worthwhile edit and worthwhile community time spent checking it.
This avoids you leaving something else to edit that someone else would/might have to spend more time on.
There are a couple of other things I'd have probs done too, such as add a colon after "If we cancel" (possibly pedantic, but it has been done elsewhere in the same question so retains continuity).
And "Then some childs remains zombies" - too many plural there, one has to go.
Really don't worry about it though. These things happen. Just try to check the entire question/answer in one go and catch everything you can.
