Let me take a step back and use an example. Suppose a Native American reservation puts out a document talking about how, historically, the land that the US was founded on was stolen from Native tribes. Now, hypothetically, someone could use that argument to delegitimize the US and claim all of its territory, if, like, this reservation had a massive army somehow. But just saying that would all still be theoretical.

If I say, “Taiwan claims territory occupied by the PRC” (or vice versa) I am making an objectively true statement, because they’ve made those claims formally and explicitly. But when you say that Russia is claiming all of Ukraine, that’s just your opinion about Putin’s opinion, it’s speculation. If you say that he claims Donbass, that’s a fact, because that’s something that’s formalized. But when he’s talking about history, of course his goal is to delegitimize Ukraine, but unless it’s explicitly applied to the present day, it’s not an actual claim.