Its very much alive. Except in case of actual WW3 (in which case all bets are off), globalism and the integration of the global economy is proceeding at an unprecedented pace. There is a reason why tariffs are only temporary and there is no legislation to enshrine them into law.
The biggest economic winners in the past 70 years or so have been economies which have integrated their supply chains with the global one in some way or the other. Its the golden goose that keeps giving (although what the countries end up doing with that wealth, whether they distribute it well, is another question).
The goal of the AU is to build better efficiencies within the African continent to the benefit of African economies. This may e.g. make African manufactured goods more competitive than the ones imported from abroad. It allows for easier building of supply chains within the continent itself.
As the article points out though, the main roadblocks are
> Poor roads and railway lines, violence-hit areas, strict border controls and rampant corruption are some of the obstacles to an effective continental free-trade zone.
These are all very serious (but not insurmountable) problems. The best outcome I can imagine is that as the AU supply chains are built and bring economic efficiencies, they can tap into the global supply chain to really supercharge them, make other AU countries realize free trade makes economic sense and encourage it. But I am being wayy too optimistic, seeing the history of the continent...
Consider for e.g. the ancient silk roads. The owners of the territory over which the trade route ran realized its economic importance and invested a lot in making it a conflict-free and protected zone.