There is a new update apparently rolling out for Sprint Galaxy S6 and S6 Edge users, identifiable with build no. ending with OL1. The full build no. for Sprint S6 is G920PVPU3BOL1 while that for the Edge variant is G925PVPU3BOL1.
Sprint has provided the changelog, and it mentions only one item: ‘Security updates’. The OL1 update follows OJ7 update, btw.
If you own either of these two devices, then pick up your buddy and check for the update under Settings > About > System Updates. If you didn’t update your device for a while, then it may 2-4 updates to reach OL1.
Anyway, bear in mind that if you have root access, you will lose it, and may not get back until support for newer kernel (from OL1) is available if OL1 brings too many changes.