You actually could setup your own matrix server and have them connect to that. Should be fine, as long as this person is not in some part of China where freedom

You actually could setup your own matrix server and have them connect to that. Should be fine, as long as this person is not in some part of China where freedoms are extra restricted. You could probably also get them to join tailscale. It's a VPN technically but I doubt it's blocked since it's not marketed as a mass market service. Edit: you could also setup a web chat that's outside of China, like one of those customer support chat widgets. It won't be e2e, but the TLS connection should protect against China's traffic inspection while also being incoquious. Whatever you say on Wechat is logged forever for sure, so you might want to put it like "hey try my chat thing out" or "dave doesnt have wechat try this thing" so you're not asking them to evade big brother on the record.