I don't see anything whatsoever in that Wikipedia that conflicts with the tumblr post. Would you care to quote which part you believe is inaccurate and why? I'm curious If you're misreading or somehow misinterpreting the post.
An anarchist should be supporting the people, not one state or another
Yes, and here's a relevant quote from Anarchism and Its Aspirations, which addresses this apparent contradiction nicely:
If we understand this sense of negative and positive freedom, what appears as a contradictory stance within anarchism makes perfect sense. An anarchist might firmly believe that the Palestinian people deserve to be liberated from occupation, even if that means that they set up their own state. That same anarchist might also firmly believe that a Palestinian state, like all states, should be opposed in favor of nonstatist institutions. A complete sense of freedom would always include both the negative and positive senses—in this case, liberation from occupation and simultaneously the freedom to self-determine. Otherwise, as both actually existing Communist and liberal regimes have demonstrated, “freedom from” on its own will serve merely to enslave human potentiality, and at its most extreme, humans themselves; self-governance is denied in favor of a few governing over others. And “freedom to,” on its own, as capitalism has shown, will serve merely to promote egotistic individualism and pit each against each; self-determination trumps notions of collective good. Constantly working to bring both liberation and freedom to the table, within moments of resistance and reconstruction, is part of that same juggling act of approximating an increasingly differentiated yet more harmonious world.
We can recognize that no state is good while still recognizing the Palestinians' right to be free from oppression and genocide. There really is no conflict with anarchism, even though it may appear to be at first glance. This is one of many very common misconceptions about anarchism.