Host it on IPv6? I've never tried it, but I would think that it's just a matter of opening a hole in your home router's firewall. I don't think any ISP is doing dynamic IPv6, or at least I hope they're not, so your Raspberry PI should always have the same global IPv6 address.

Anyway, this is one of the principal points of IPv6, to not only reach the internet, but let the internet reach you.

Maybe in the future, we'll reach a point where it's common for households to have symmetrical bandwidth and host their own stuff from their home instead of having no option but to rely on VPS companies for that.