This seems more a problem with the culture. Where I've worked, messaging and emails are used for non-urgent, handle this when you're available type notices. If something was urgent, we walk up to their desk and tell them. Slack actually cuts down on desk-related interruptions; we'd literally just Slack each other even though we're sitting across.

Water cooler conversations are a kind of stress dissipation response for some people. It's great for some, bad for others. Slack means that it stays in a channel instead of at the water cooler when all you want is a drink, not a chat.