It's not like there are only two buckets:
1. HFT doing ass-simple arbitrage where only latency matters 2. More sophisticated slower trading taking in deeper signals
Those are two points along a continuum. If you are reacting to an earnings announcement by having an LLM read the earnings release and listen to the call, getting the results a few seconds earlier lets you get your trade in a few seconds earlier. Just because "not HFT" doesn't mean "completely latency insensitive".
Exactly that. Except that ultrafast delivers this level of intelligence an order of magnitude faster. So if your competitors automatically react to news articles or financial statements with a certain level of comprehension within minutes, you can now do so in seconds.