Merging bottom PR with squash causes conflicts on the stacked PR

[gabrielb-broadsign]

Using stacked PRs with the squash merge strategy, after merging the bottom PR of a stack, the top PR ends up showing merge conflicts. I suppose this could happen on any partial stack merge.

Context / workflow:

1. feature-1 branched off main, opened as PR#1.
2. feature-2 branched off feature-1, opened as PR#2 (stacked on PR#1).
3. Merged PR#1 into main via squash merge.
4. PR#2 now shows merge conflicts against the updated base.

Assuming this works as intended when merging the whole stack, the same strategy should probably be applied to update the PRs left unmerged when merging the stack partially.

Can you confirm this is expected, and if so, is there a plan to auto-update/rebase remaining stacked PRs on partial merges the same way it presumably happens on full stack merges?