From memory there was nothing documented about the Aksumite kingdom in greco-roman writing until 0100 AD and it was a greek who's name I forget who had some flowery prose about it being a major ivory trading hub at that time. Also the Aksumites didn't have their stuff together as a kingdom until 0100 or so. Although I also remember some roman writing about it being an iron hub much later. It was a major trading partner of rome... if the land route wasn't nuts they'd probably have ended up a province. They grew close, really close.
I suspect what happened is the journalist filter input something like "artefacts dating from 150 BCE" and output "artefacts dating from the first and second centuries." To take out the technical stuff, make it more mass market, simpler, more least common denominator. However most people assume a date like 2015 or "2nd century" means AD/CE and this is extremely important in context.. Trade with the romans in 200AD when the kingdom was flourishing would be the most boring story ever, but proven trade going back to 200BC before there was an organized Aksumite nation is a pretty cool story.
Being a really likely sounding narrative doesn't prove its true; could be some kind of proto-Aksumite site in 90 AD before they got their stuff together as a kingdom. That might make an interesting story of its own. I always figured the Aksumites got their stuff together and then started trading with the Romans some time later, once their economy stabilized and they had the basics down and some surplus to trade. The actual story might be the romans helped them get their stuff together by injecting trade goods so the cause and effect are flipped. That is a pretty cool story, but again, sounding likely or cool has little to do with truth. Still, if true, it would be a heck of a story.
Someday when it all settles down and gets documented, it probably will be a cool story. We're just not going to get the cool story from mass market journalism.
I'm sure that this quote was cherry-picked, but it reads like this is a discovery of some previously unknown revelation:
> “Ethiopia is a mysterious place steeped in legend, but nobody knows very much about it,” said Schofield. “We know from the later Aksumite period – the fourth and fifth centuries, when they adopted Christianity – that they were trading very intensely with Rome. But our finds are from much earlier. So it shows that extraordinarily precious things were travelling from the Roman Empire through this region centuries before.”