THE SITUATION
The Web Client is likely to be deprecated by October 2019 with a view to be discontinued a year later

Dynamics 365 Unified Interface Playbook

In the immortal words of Jules:

Oh, I’m sorry, did I break your concentration?

Yes, the legacy Web Client is going away. Want to know more? Head off to Unified Interface Community and read excellent Unified Interface Playbook, Transition Whitepaper, and all other goodness.

You’ve been warned.