According to ChainCatcher, Cosmos Hub posted on X that the community had previously voted to introduce the fee market module (Proposal No. 842) to Cosmos Hub.

The team has now completed the integration, and as part of Gaia v18, it will provide an adaptive fee market and also support ATOM destruction. The new fee market mechanism will only start adjusting fees when block capacity usage exceeds 50%. In short, fees will only increase when block usage exceeds 15 million Gas units.