Isn't caskroom/cask tap migration in update-report too aggressive?
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`update-report` does [this](https://github.com/Homebrew/brew/blob/a3bffe70bcf33e6051140b1a93c9f48714605af6/Library/Homebrew/cmd/update-report.rb#L478-L479]) when a formula is migrated to caskroom/cask (this happens automatically):
```rb
ohai "brew uninstall --force #{name}"
system HOMEBREW_BREW_FILE, "uninstall", "--force", name
```
IMO this is way too aggressive. Uninstalling a formula without user's consent (I assume most users won't expect their stuff to be auto-uninstalled when running update; I certainly didn't when it happened to me) is bad enough; I don't know what to say about the `--force` flag without making myself look bad.
Note that the formula need not be uninstalled (let alone force uninstalled, wiping out all kegs), because kegs do not interfere with casks. IMO an unlink is as far as we should go. Also note that the cask => formula migration logic immediately above the logic I'm calling into question doesn't uninstall the cask.
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On a somewhat related note, I think cask => formula or formula => cask migrations, or at least the parts that auto-installs stuff, should be guarded by the `--preinstall` exemption. It's plain weird to have unrelated things installed (and worse still, uninstalled) when you run some command other than update or upgrade. Check out my horror story below.
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To put things into perspective, here's a little horror story of mine. I was running `bump-formula-pr` just now, unsuspectingly. Then `brew` decided to `uninstall --force` my `keybase` kegs, run `brew prune` without my consent, and install the `keybase` cask, which prompted a GUI password dialog — due to the one time setup run by the cask's postflight — and a Little Snitch dialog about the newly installed app attempting to make Internet connections (look, I'm not arguing the cask shouldn't be auto-installed — which could be a separate topic — but it is indeed crazy when these all happen during a `bump-formula-pr`).