The idea that the same agribusiness companies making spam will put in the work to make a fully optimal replacement for natural meats our species has eaten for millenia is far fetched.

We're still discovering beneficial nutrients every year (carnosine, carnitine, taurine). Vitamin K was pretty recent.

We're running the biggest medical experiment in history taking an apex predator species off meat. As meat consumption has dropped most chronic disease has been going exponential despite following agribusiness and exercise guidelines.

It took decades to 'prove' cigarettes were bad because it threatened big money. There is orders of magnitude more financial interest in fake meat. It could take decades to actually conclusively know the long term effects but the industry will declare it safe long before that.