I've seen such reading groups. I worked for Atlassian, and there was a reading group. My impression is it was organized only as a low effort just to demonstrate that IC is going extra mile for the company. The quality of such reading groups were quite low. And it was expected that you would attend this reading group at a lunch time. You're taking your lunch with you, and instead of enjoying your meal, you're cramped in a small room with coworkers who also got their sandwiches and sugar soda. Horrible experience, and zero value.