After creating a Text2D object when setting the isVisible field it seems to have the reverse behaviour to expected and documented.
When setting isVisible to True the text disappears from the scene. When setting to False it appears.
Seen with the 2.5 release.
Documentation, I know I've quoted 2.4, but the 2.5 makes no mention of this field and there is no deprecated warning showing when running with 2.5 js:
https://doc.babylonjs.com/classes/2.4/text2d
Playground example, comment out the commands at the end of the code.