Jetpack doesn’t block XML-RPC traffic as it uses XML-RPC itself. The protect module of Jetpack detects brute force attacks from the common XML-RPC attack vector. Jetpack will then prevent 90% of the database queries and reduce the load on MySQL. However, it’s still possible for enough XML-RPC attack traffic to exhaust MySQL’s resources.

If you are not using Jetpack for anything else, I would recommend using the other methods mentioned in the link from your question. If Jetpack is essential for you, I have seen WordPress plugins that place a hard block on XML-RPC traffic, but whitelist Automattic’s IP ranges so Jetpack continues to function.

I hope this helps!