One of the changes going into the July update is a transaction fee change that burns (throws away) part of the transaction fees. That will put some deflationary pressure on total issuance, while at the same time, when they switch to the staking chain total new issuance will be drastically cut since running a validator is far more efficient then mining.

What the long term inflation rate will be then is really set by the demand for transactions and how much congestion there will be on their network, driving up transaction prices and fees burned (or not).