In most places, you do not have to meet current egress requirements on a replacement window installation. This applies to insert windows too.
In some places, they require you to do a full frame replacement down to the studs, even if that doesn't end up meeting egress requirements. They just don't want you losing any of the egress space you already have.
There are also places that require you to meet the new requirements for egress, even in an old home. That can require cutting your openings much bigger and even possibly having to install new headers. It can be an expensive undertaking depending how many windows you have that need egress. Sometimes it will look funny only making some of the windows that large, so you my need to enlarge others as well just to match the look of the others.
As you can see, the requirements can be from nothing to strict requirements.
If you are in any doubt, it is imperative you get clarification from your local code enforcement as to the requirements in your area.
Also, a village official may tell you they follow something like the International Residential Code 2000, but before you take that as gospel, know that the city or village may have amended a portion of the code to deal specifically with windows. Make sure the person telling you is not just a clerk. I've been burned before by listening to clerks at the city code and building permit office.
Do your research.