Discovery
The phase where a project gets defined has been reworked around the work you actually do in it: moving through the steps, reading and editing the documents it produces, and signing them off.
Discovery is where a project gets defined, and most of what changed is how it feels to move through. A new project opens on the step it is on rather than an empty dashboard, and the path from the first conversation to a published document set follows the order you take it.
Reading and editing those documents got the same treatment. A long document is easier to navigate and to work through a section at a time, and a draft stays yours until you publish it, so there is no cost to leaving one open and coming back.
A document can now be marked reviewed. Until now there was no way to say you had done it: the inbox raised an item per document and nothing a person did closed it. A review now records who signed off, clears that item, and points at the version you actually read, so publishing a new version asks for review again rather than carrying the old sign-off forward. Reviews are recorded in the audit log.
Also in Discovery
Publishing a document is recorded in the audit log; the approval that turns a draft into the governing version used to leave no trace
The contents list links to a single section and lands on it, which on a long document it previously did not
Project knowledge uploads no longer stick at Queued with no way to remove them