Those aren't terrible per se, but I think the relentless immediacy of you're manager's chat or request would get annoying, especially on a weekend or holiday as the article discussed.
At my last job, we were expected to monitor the Slack channel, and jump in to help - when we were off shift, at the store, day off, vacation - oncall was the first person paged, then whoever was awake. And this is to answer customer phone calls and emails needing cloud technical support, and the occasional 3am VPN tunnel rearchitecture.
On the other side, when the line laying union threatened to strike, they told us we'd be working 12 hour days and help out laying line during the strike.
