Cleaned for the first time in 5 years

I doubt that. The placement of the lighter ones is the exact same and as for the grey ones on the side, there even is the same one cut in half.

High powered pressure washers can do amazing things

The photo resolution isn’t high enough to make a positive determination. It’s also possible they were painted after cleaning. Pressure washes and other methods can get impressive results. Looking at the sides though- you can see there were plants growing up through the cracks between the bricks. Most pavers use a polymeric sand or other fill like mortar to keep their shape and prevent in growth and water penetration. In the after photos the weeds are gone but it looks like (on my tiny screen) the cracks have been filled in. So I wouldn’t be willing to conclude that the stones were replaced, but I suspect it was more than just a simple cleaning and likely involved more. But again- with such low res photos and a small screen its speculation. It looks way better either way and I hope they are proud.