Elon's been saying this from the beginning, he understands that is what will happen. I imagine part of being able to move forward with big ambitions is you have to make peace with that fact - otherwise fear of the unknown, of competition, will easily overwhelm you.

My understanding was that the Gigafactory was conceived out of necessity as least as much as opportunism. That is necessity for a large stable source for batteries over which Tesla has quality control. Had they been able to find that elsewhere, they wouldn't necessarily be in the battery-making business.

All that is to say, I think (hope) that Tesla doesn't see what is essentially a commodity business--albeit one with some innovation baked in--as a driver of their enterprise moving forward. As such I think they should welcome competition in that space.

Not for other battery makers like Tesla, if they overestimate demand and flood the market with cheap batteries.

Depends on how much they've committed to their gigafactory.

The article implies that the Chinese batteries will be of equal or better quality than the ones Tesla manufactures, which is a dubious assumption. Cheaper goods are a good thing for everyone, but I can't believe up front that China will be able to match the quality required for a Tesla vehicle.