What happens to Hide My Email emails if you cancel iCloud+?

I've started using the new Hide My Email feature in iCloud+. Though I've thought about canceling my iCloud+ subscription. Apple's website says the following: "If you downgrade to the free iCloud plan, ... you will no longer have access to iCloud+ features like Hide My Email, Private Relay, and HomeKit Secure Video support".

If I already have Hide My Email email addresses made, will I stop receiving emails from those email addresses if I cancel my iCloud+ account?

Hide my email is essentially a email forwarding service. If you cancel iCloud+ it is likely these "Hide My Email" addresses will stop working. Even if this doesn't happen immediately you still run the risk that they will be silently disabled at some point in the future without your knowledge and you will lose emails that would have been received.

If you are prepared to accept the risk of this happening then you could carry out a test by signing up for a free trial account of iCloud+ and then cancelling or letting it expire to test what happens.