So both these settings are not usable right now (if I don’t want to disable tips as well) as it would confuse a new user on the very first interaction.
I think the welcome message refers to Discobot’s PM, not the new user tips (so is this by design?). I think the setting you’re looking for is enable user tips, which disables new user tips.
I don’t want to disable user tips. But I’d need to if I disable the welcome message, as currently the tip for the welcome notification is shown, even when there is no welcome message.