Description of problem

Back when OCPBUGS-17709 was documented, clusters didn't add the control-plane role labels to pre-existing control plane Nodes when updating from 4.11 to 4.12. But since then, the OCPBUGS-58180 series has added that labeling, and we should drop the docs that claimed the labeling didn't happen. At least in 4.20. In 4.19 and 4.18, things are made somewhat harder to explain due to the fixes landing in patch releases.

Version-Release number of selected component

The labeling fix landed in OCPBUGS-58180, (4.20.0), OCPBUGS-58820 (4.19.4), and OCPBUGS-62321 (4.18.z, not yet released).

How reproducible

Always

Steps to Reproduce

1. Install a 4.11 cluster
2. Update all the way to 4.20.
3. See the control-plane role labels.
4. Read the 4.20 docs.

Actual results

The docs claim the control-plane role label needs to be manually added.

Expected results

The docs probably don't need to talk about the 4.11 to 4.12 label transition at all, now that modern clusters reliably have the modern role label.