These satellites should be in low enough orbits that any junk from them burns up in the atmosphere as their orbits decay. Maybe there could be an issue from collisions in low orbit pushing objects into higher orbits but those likely would be erratic orbits with low points that still subject it to decay.

OneWeb's constellation is high enough that it'll take a lot more than 25 years for any satellite that fails to deorbit itself to decay. On the way down, these debris will cross the ISS orbit and the most popular sun-synchronous orbits.

Starlink is lower, but still above the ISS and the SSO at 282km.