Azure P2P Server Showing In App Registrations. Seems suspect/fishy.
Yes; it is legitimate. P2P Server is automatically added after a Windows device is successfully joined to Entra ID (EID). It enables RDP authentication for EID Joined devices.
NOTES:
https://www.jasonfritts.me/2019/09/26/what-is-the-azure-ad-service-principal-p2p-server-for/
https://learn.microsoft.com/en-us/entra/identity/devices/faq#what-is-the-p2p-server-application-and-why-is-it-registered-in-my-tenant