Earlier quoted context omitted.
When I see Slack as a support channel I almost certainly won't use the support, and I'm less likely to use the product. At least I can organize and search emails by default, and it's relatively private. It's annoying having to anonymize my issues for my employer so I can publicly request support.
Did you even read the article? This is about offering companies a private 1:1 slack channel between your team and the support/sales team. Many companies offer this nowadays if you're on a large enough plan to be assigned an account manager and I prefer it >100x to email because I know a human is going to be in the loop.
I get that it's a preference thing, so I'm not saying my position is correct for you. If you don't care about any of these things, I can see Slack being better.
"Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that"."