Technically they still are, but the nonprofit owns and controls a for-profit corporation. I think they made that switcheroo a little over a decade ago, but someone else can fact check me the timing.
Is that an actual for-profit company controlled by the non-profit wikimedia foundation, or just a way for the foundation to make money to run its operations? My understanding is it's the latter, unlike Mozilla and now Raspberry Pi. See here:
Wikimedia Enterprise is a product of the Wikimedia Foundation, with content created by volunteers around the world.
A nonprofit doesn't have to rely exclusively on donations to fund its operarions.
it's not. They do have a commercial product they use to fund their operation, in addition to donations, but that doesn't make them a for-profit company.
I just took some time to watch that video, and that seems to say "Yes" instead. Yes, they started as a non-profit, with a for-profit arm, and Yes, the for-profit arm is now trying to sell out in an IPO to (guess what) make more money. And while they are distinct entities, there's some of the same people on the board for both, who are likely going to profit.