The Lingering Sentiment's words were referenced, albeit in the most vague of ways, by Nomura himself in Another Report, hence canonizing them.
Nomura said there was a hidden reference to Riku being a chosen wielder in the FM+. The LS saying he did not choose Sora for the Keyblade leaves us with Riku yes being chosen. It makes sense in light of what was said in KH1 (since Riku was said to be the original wielder, so if the LS didn't choose Sora for it, it makes sense he did choose the original wielder), and confirmed further by Nomura's words.