Modern web UI is nice, but at the end of the day when it comes to mobile, apps are still king.
If the purpose of this is to replace the interaction we had on Yammer, a mobile app is a necessity...
I'm not surprised and baffled at the same time. I've never truly expected a mobile app anyway. I'm still surprised that Microsoft took a plunge on a platform while its vision said "mobile first". It's 2018 and Microsoft scrapped the "mobile first" vision, so at least that's consistent.
As a former, very active mobile, Yammer Network user, my usage here dropped to about 5% compared to previously. And I don't think it'll ever spike to Yammer levels, since there is no mobile engagement here. Many of the first pain points since launch still exist in the web version.
I've resorted to just reading the blogs here, mostly because Microsoft migrated them from blogs.office.com to here.