> If you live in Europe, this restriction may be considered "gatekeeping" and exempted by the Digital Markets Act.

That's not how the DMA works at all, there is no concept of gatekeeping practices. Instead, the EU Commission designates companies that act as gatekeeper for some services (current list here: https://digital-markets-act.ec.europa.eu/gatekeepers-portal_...) which then puts constraints on what they do.