What YAML is
YAML uses indentation instead of brackets. It is a superset of JSON, supports comments, and is meant to be edited by hand.
Kubernetes manifests, CI pipelines, Ansible playbooks and most modern config files.
What MediaWiki is
MediaWiki table markup opens with {| and a class, marks headers with an exclamation mark and rows with |-.
Wikipedia editors and anyone running a MediaWiki install.
What changes when you convert YAML to MediaWiki
A YAML list of maps reads as rows and columns directly. Anchors and aliases are resolved before the table is built, so a repeated block arrives expanded rather than as a reference.
The wikitable class is applied, which is what gives the table borders and header shading on Wikipedia.
What carries over from YAML to MediaWiki
YAML records 2 things about a table that MediaWiki has no way to hold.
YAML distinguishes a number from the text of a number; MediaWiki does not, so every value arrives as text and has to be re-parsed by whatever reads it next.
An empty cell and a missing one are the same thing in MediaWiki, so a null and an empty string in the YAML both come out blank and can no longer be told apart.
MediaWiki marks header cells differently from data cells, so the keys are lifted out and written once as a marked header row rather than repeated on every row.
The identifier 007 comes out of the MediaWiki as 007. Reading it as a number would have made it 7, and an id that changes value is worse than one that stays text.
The role "Analyst, data" survives with its comma, in one cell rather than split across two. That is the first thing to check in any converted table, and the usual place a MediaWiki file goes wrong.
The quotes around Jonah "Jo" Pryce are left as a plain quote character in the MediaWiki.