Your use case

When a user follows a matrix.to link on mobile, it doesn't work because the app does not keep the link. Storing the link in the clipboard means it can be pasted to ensure the user reaches the room they intended to...

More information here: element-hq/element-meta#534
The Delight team roadmap (internal) also has more information: https://docs.google.com/spreadsheets/d/1SAcCgnHoze9Flqx-XXkC0B8iQyLnpylv2z4iidK0v-8/edit#gid=42666095&range=C23