I didn't delete this, but I think I can understand why the mod who did chose to do so. The main issues I see with your answer are:
It doesn't actually provide an answer. It comes very close and, to someone with a very technical background, it could even provide an answer, but you don't actually come out and say it. So, instead of
You’ll find the abbreviations that are used by the indicator in the /usr/share/X11/xkb/rules/evdev.xml file in the tag.
It would have been better to simply make the answer explicit:
You’ll find the abbreviations that are used by the indicator in the /usr/share/X11/xkb/rules/evdev.xml file in the tag. Changing the values there will do what you want.
More importantly, you're not actually providing anything not already mentioned in the accepted answer. Yes, yours is a streamlined version of it, but since it isn't adding anything new, it would have been more useful as a comment on either the OP or the answer. Alternatively, you could have suggested an edit to the answer, similar to what the answer's author has now done.
In all, and given that the answer now has the sort of summary you seem to have wanted, I think the mod who deleted was right to do so since your answer wasn't adding anything to the post.
Finally, thank you for coming here and posting a calm and civil request for explanation. That is very much appreciated!