I hate this approach (even more so when I was involved in writing the written communication) because it usually turns into idly waiting for others to finish reading, while I get distracted, bored and just plain could be doing something more productive.

I understand the concept and some people must find it useful and valuable, but I’ve personally never got anything of value out of it other than making sure everyone has read the content before the meeting proper starts. Personally, I find asking somebody to attend a meeting, where 20 minutes is just silently reading, rather disrespectful of their time.