Hey @Axl-ArrasDev,
Unfortunately not. You’ll need to make an additional request to GET /crm/v3/owners/{ownerId} to pull the email (and other information if needed i.e first and last name). See Owners API for more information.
I believe the reason for this is how the “Deal Owner” property (or any owner property for that matter) works in HubSpot. It is storing the owner ID behind the scenes.