Do end users need formal training on Office 365 apps?

HI Graham McHugh - This is a great question.  I'd encourage you to redefine what "training" means in our current environment. What we find is that many people are unlikely to attend an actual class but the demand for short videos that are task or scenario based is high.  Think "playlists" like on Spotify or on your music library.  People need to know something exactly when they need to know it so we're going that direction overall. 

That being said there is always some demand for virtual or instructor based training that helps people "get" the basics of what the new experience is.  45 minutes seems to be a sweet spot for these trainings.  The virtual version is good because we find people stop and start the trainings to try things in the product.  Also it's a best practice to establish internal Champions and these folks usually are highly engaged in more in depth training.  

Remember all training needs to be in the context of what's in it for the users themselves. What I think is super cool may not help someone else in a particular role.  This is why we're so fond of the playlist model and integrated this into our Custom Learning for Office 365 training site template which will be broadly available in Q1/CY19.  This SharePoint Online site template with a custom Webpart will allow you to customize the playlists, included products and look/feel of the experience and it's easily pinned in Teams.  We'll announce its availability here and in the Driving Adoption community as well. 

At the end of the day this is our chance to increase the digital literacy of our workforce and (as I always say) get people to STOP emailing that spreadsheet around!  Hope this helps.