And global access to non-native food sources exists since the 15th century.

The difference is whether mostly everyone has access to it.

So yeah. I'd say he's right and I'd bet your fancy shmancy genetic engineering won't wield anything significant but for a residual percentage of very specific cases.

As has most medical technology. The overwhelming majority of diagnostics are still made via question/answer, palpation and hearing.

Mass promiscuity has consequences, just like poor sanitary habits have them.

No amount of technology will change that.