They may also just use egress. You can easily to check that - hover mouse above graph and you will see is it egress or repair. If repair - it perhaps moving to geofenced nodes, if egress - it is a regular usage.
The deletions happen every day, I did not see any spikes in that, except when EUN-1 and US2 were decommissioned: Announcement: Storj to shut down europe-north-1 and us2