The only "special" pipe I know of for a washer is possibly the vent pipe. This pipe runs up and, eventually, through the roof, allowing sewer gases to vent outside and not in your wash room. This needs to be between 6’ and 10’ from your washer drain. Most things utilizing a home’s drain system also fall under this rule, but most builders try to align the units so they can easily utilize one or two vents. The difficulty comes when an item is being relocated, such as in the case of your washer. Maybe the plumbers noticed this, and were just telling you your new washer location required a new vent stack.
Although the material used for this pipe is not special around here (1 ½" PVC is sufficient), maybe there is something special about the code in your area. My home is also all galvanized and iron, but adding PVC is perfectly fine.
Now as far as your galvanized pipe question, this is also easy depending on what your municipality requires. Again, I would simply cut out a 2" or so section (location depends on accessibility and drain-ability) and add the appropriate PVC adapter. Some would also simply use a rubber tee which clamps on, but I prefer not.
I would suggest getting more details from the plumbers, and then post toe details to us for further review. Also, check with your municipality for details. They can be an invaluable source for information and requirements.