Hi @Nick_Cable, thanks for reaching out!
We are currently running an experiment to improve the zoom functionality for Timeline and Gantt views and the change that you see is part of it.
You are right, the ability to view project timeline and gantt has been limited to a default display of approximately 6 months at a time. With this update, we are introducing an enhanced zoom functionality that allows you to zoom in for just a week or zoom out to see the big picture scale of a multi-year project.
I will share your feedback with our product team so they can consider adding an option to display 6 months.
Let me know if you have any questions!