Good news! You do not have to update your Zotero account or app for OpenAthens. However, if you use the optional Zotero Connector plugin for your web browser, you may have to adjust one setting there.
If you use the optional Zotero Connector plugin for your browser, be sure not to use the "Enable proxy redirection" feature with our old proxy server. This can prevent you from accessing GW's subscriptions!