Yes, Asterisk can poke holes in NAT on its own just fine. I was surprised how pessimistic the article is on this. I have systems running for months and years behind NAT with no issue. You might have to disable direct media (endpoint/disable_direct_media_on_nat).

Also, this is just uptime related tip not NAT, you must explicitly set registration/max_retries to a huge number otherwise Asterisk just gives up permanently at some point. It’s a really weird default.