There’s a similar law where you must at least defend a trademark against misuse to keep hold of it. That was the reasoning behind this music video for Velcro:
So, based on that, maybe they won’t lose it just by not using it. But if someone else tried to establish a Twitter product, they may lose the trademark if they don’t fight it.
Is there a law that you must use a trademark to keep it?
There’s a similar law where you must at least defend a trademark against misuse to keep hold of it. That was the reasoning behind this music video for Velcro:
https://youtu.be/rRi8LptvFZY
So, based on that, maybe they won’t lose it just by not using it. But if someone else tried to establish a Twitter product, they may lose the trademark if they don’t fight it.