I don't imagine beer production requiring such high temperatures, but honestly I don't know anything about industrial beer production. Anyhow the tech presented in the article is very cool.
It's not the universal storage solution to end all search for other storage solutions because it's only really applicable in a niche (heat consumption), but that niche might not be as small as people think. I think that besides applications that require high temperatures it could also be a very good match where a particularly high maximum temperature isn't required (so heat pumps and the like could be applicable) but peak power demand is of a rarely occurring, intermittent nature. It might even be applicable to once-in-a-lifetime heat applications if they can be designed for easy oxide recovery.
What remains open is how cheap "charging" throughput can be built, as this is the weak spot of all other power-to-fuel concepts: the conversion facilities tend to be too expensive to remain idle outside of electricity oversupply times. And who knows, theoretically conversion throughput capacity might even turn out to be so exceptionally cheap (I certainly wouldn't expect that, but I'd be glad to be surprised) that even the inefficient electricity->fuel->heat->electricity might become competitive, once conversion outgrows direct heat applications. A market for inefficient but cheap long-term storage would definitely exist if there was any supply.
Another example for how electricity is a very valuable type of energy.
Seems like an engineering challenge to me not an actual limitation.