About the question in the topic title: No FP2 is not open (source) hardware, but that was not the question you really wanted to ask.
I think “designed to open” is a valid statement, as you can and should open your FP2 if you run into issues. You can marvel at the inside, clean the connectors and replace modules, but of course the design could be “opener”.
I guess if you open up a module even more you only loose warranty on that module, so you can decide for yourself if you’d rather get a free replacement on warranty or try to repair your module yourself to reduce your carbon footprint and e-waste, but if you fail have to buy a new one.