Upgrade plan should address merge strategy for long-running branches

[mikadumont]

Description

A customer performed the upgrade on a fork of a rarely-touched area, but during the migration the main branch underwent changes. The team struggled to merge the upgraded code back due to accumulated drift and felt overwhelmed trying to reconcile the differences.

Expected Behavior:

The upgrade workflow should include guidance or tooling for merge strategy, such as:

• Recommending in-place upgrades on a branch rather than a long-lived fork
• Suggesting periodic rebasing checkpoints during multi-week migrations
• Using Copilot to assist with merge conflict resolution after drift

[SanyamSavla]

@mikadumont @vijayrkn @abpiskunov
merged the PR with changes.. so closing this issue