I've updated some pages that I suspect are the most important:
https://wikitech.wikimedia.org/wiki/Help:Accessing_Cloud_VPS_instances
https://wikitech.wikimedia.org/wiki/Help:Access_to_Cloud_VPS_instances_with_PuTTY_and_WinSCP
https://wikitech.wikimedia.org/wiki/Help:Horizon_FAQ
I'm hoping someone with better mediawiki skills can do a search and clean up other stragglers.