In my opinion, relying on blaming Wikipedia for copyright breaches is a terrible idea. Wikipedia is open to any contributors, just like Medium. Use creative commons images or public domain images if you cannot create your own. They may not be 100% safe, but it's much better than taking copyrighted images and hoping for the best.

Unsplash is built into Medium for this purpose. Taking images that may be copyrighted and thinking that just because someone else has broken the law and linked to the source it's Ok for you to do the same, is very dodgy. Of course, if the one on Wiki is CC, it's probably OK.

I've got a list of copyright stories here, which will make you cringe and you'll want to be careful.

Van Gogh is long dead and copyright only lasts 70 years after the death of the author, so I don't believe there's a problem with his images. But I'm no legal expert.

https://medium.com/@susiekearley/list/copyright-f00f7970fd12