I would not consider that shadow banning or even banning. The user had their notes accepted by some relays. I think the lesson here is that relay management needs to improve. The UX is lacking as evident by his experience.
A new user who is getting shadow-banned from nostr:
How can we improve this? I think the main fault is with primal here (just because nostr:nprofile1qy2hwumn8ghj7un9d3shjtnyv9kh2uewd9hj7qghwaehxw309aex2mrp0yh8qunfd4skctnwv46z7qgwwaehxw309ahx7uewd3hkctcpr9mhxue69uhhyetvv9ujuumwdae8gtnnda3kjctv9uq3zamnwvaz7tmwdaehgu3wwa5kuef0qqs92xycp9kys8cqyx09e9pfnggaj9prjjwd67t6t7zs3ra4fyh2u4gv4c4d0 is using it), for blocking notes from its own users, and not showing relay publish failures (maybe?). But the criticisms apply to all clients.
Probably the root issue is that relay policy is hard to infer via nip 11 and notice/ok messages. It's also one of those unglamorous chores like error handling that no devs (except go devs) enjoy.
Discussion
Since amethyst has the inbox model I often see my posts getting delete. I don't understand it at all.
It's like witchcraft for me at this point