Yes, our expectation is that email solves the problem of notifying reviewers. If email isn't solving this problem, we'd prefer to try to fix that rather than add features to support a workflow where you manually copy-paste links into a Slack channel, since this is a fundamentally narrow, unscalable workflow and the feature isn't practical to implement in environments where arc is run on a remote host.

See T920 (we could SMS reviewers instead), T11069 (we could post to the Slack channel directly), T5726 (you could write a more sophisticated channel filter with hooks), T10448 (we could improve mail filtering rules), etc. Beyond this future work, substantial tools already exist to manage notifications (Herald, Owners, Projects, API, tools within Differential, etc).

This request doesn't provide enough context for us to find the best solution we can to your problem, or to suggest alternative approaches or workarounds, or anything else. (See also Describing Root Problems.) We will essentially never implement a feature without fully understanding the problem it's solving and the context the feature exists in.

Feel free to file a new task if new problems crop up after looking at how email is currently failing, but please provide us with as much context about the problem you're facing as possible. Generally, you should be able to suggest at least three different ways we could implement to solve your problem, as I have above. If you can't, your problem description is likely too narrow to provide us with enough context.

Very narrowly, note that --browse will open the revision in your browser, and ⌘+L will generally select the address bar, so you could arc diff --browse, ⌘+L, ⌘+C, ⌘+V to avoid using your mouse.