Any increase to interest will mostly go to exchanges unless there is a massive movement off exchanges, which seems unlikely.

HF25 solves this with interest getting paid only on savings. The exchanges can put the assets in savings, but by doing so they need to wait 3.5 days to withdraw it and so most shouldn't. Exchanges could offer staking incentives to users and stake it themselves, and send users a % of what they get.

The fork honestly shouldn't be too far off. Raising it now might mean they get a month or two of payouts before the switch occurs, and from what I see, some witnesses want to go even higher, but only after the fork for reasons like this.