That sounds fair. I’d be happy with either a confirmed infection or an antibody test. As long as it is verified.Well I'm opposed to mandates in most cases, but if vaccinations are mandated, natural immunity should be considered as an acceptable alternative since it provides superior immunity. All that should be necessary would be proof of an infection, which would be easily attainable from your healthcare provider, just as a vaccination card is. Antibody tests aren't being required for the vaccinated so it shouldn't be required for the naturally immune. In both cases immunity likely wanes over time, but there doesn't appear to be any substantive evidence of which one provides longer protection.
I would still suggest that its preferable to get a vaccine even if you've been infected. However, having natural immunity is a good faith objection to not getting vaccinated.
There is also a strong argument that it is unfair to vaccinate known recovered patients while almost all of Africa is unvaccinated.