Getting My First Watch Serviced

[Generation]

I took a watch in to get serviced for the first time. It has a standard ETA movement. It's now being sent to the manufacturer's service center. Some questions:

1) The person who worked at the service desk kept saying the service center would "swap" the movement. Does anyone know what this means? When I asked the person, he said they will look at it and decide if it needs a completely new movement or if they will fix the old one. But he kept saying "swap" anyway. I was under the impression that for servicing they always just took apart the old movement and made it run new again. Could someone elaborate on this?

2) It's been about seven years since I bought the watch. The service center people said it was due for a servicing; but the watch dealer at the retailer said he generally advises people to wait until something happens to the watch before getting it serviced. He said the manufacturers suggest 5-7 years, when in reality they can go much longer. Can anyone elaborate on this, too?

Thanks in advance!