[marten-de-vries]

I think 'rearchitect' should be interpreted as 'redesign the UI', not as 'start from scratch'. Most big changes seem limited to the UI (and done as part of a Qt -> QML migration). And it looks they'll do even those piecewise:

> In order to get the release of 4.0 out as fast as possible, we will be porting over many of our less used interface elements and dialogs directly from MuseScore 3. The plan is to gradually replace these with redesigned versions (built in QML) in subsequent releases (4.1, 4.2, etc.).

That doesn't sound unreasonable to me.