Yes, but he most definitely has the money to buy the patent and then open source it. Sort of like he did with Tesla.
They phrase it as having 'an open-source philosophy', but what it really boils down to is that they continue to file patents[0], but choose not to use those patents in an anti-competitive manner, only 'defensively' (on their word).
Now this isn't attempting to conflate patents with 'open-source', but that ship sailed after Elon's memo regarding the concept in 2014.[1]
[0]: https://ppubs.uspto.gov/pubwebapp/static/pages/ppubsbasic.ht... [1]: https://www.tesla.com/blog/all-our-patent-are-belong-you