So are these laser equipped says inserted between/within the "chain" of previously deployed starlink says?
As the sister comment implies though, Starlink sats are in low Low-Earth-Orbit (LEO) so they experience non-zero drag from the atmosphere. This slows them down, causing them to gradually fall back to Earth, creating a natural expected service lifetime for each satellite in orbit.
So the expectation is that SpaceX will have to continually put up more and more replacements indefinitely as older sats decay and burn up in the atmosphere. These 10 laser sats are just the latest among a string of sats that are yet to come online with newer and better capabilities.