You are in control of where your usage statistics are being stored. For example, you can choose to have XWiki Cloud but host your own self-hosted Matomo server. If you do this, your XWiki data will be hosted by OVH and your analytics data, the one that Matomo collects about usage of the XWiki instance, will be on your self-hosted Matomo server.
Committed to transparency, we develop our products openly with a public roadmap. We value your feedback and feature requests, so please don't hesitate to share them with us.