I cannot watch the interview right now, but the way the sentence is written in the article, it reads equally possible to me that this was in reference to other frontier models on the market or compared to GPT-5.5. The former I'd instantly believe, the latter I am very skeptical of.
I'd be very impressed if they actually managed any reduction as 5.5 is already obscenely token efficient to the point that the reasoning traces seem to compact far less reliably compared to 5.4 as they've become barely comprehensible gibberish.
As more reliable compaction is a stated goal for 5.6, if they solved that and got token usage more efficient on top, that'd make the price to performance equation very much in favor of OpenAI over any other lab. 54% more efficient vs 5.5 would make the pricing for a full benchmark suite run competitive with open-weight models, even if we assume higher per token costs.