I don't expect massive changes.
The reduction in interchanges is mostly because the stricter enforcement of the concussion rule meant more free interchanges last year and this is really just reigning that in.
The total minutes available on field is still the same, so I think in general minutes will be the same. Teams will still have 2 props on the field all the time, so they'll just be expected to play for longer periods before they get a break. Props that can easily play 60 minutes like James Graham will be doing that a lot.
I also think more teams will carry a utility on the bench in case of injury, and be content if they only end up using 16 players for the match