I was exploring a minecraft world in 21w42a and stumbled upon a cave near the surface that had an exposed blob of lapis ore at Y=53, while the latest ore distribution chart says that lapis should not be able to generate exposed until Y=24. Therefore, I believe this is a bug.
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See the minecraft.net graph.
Actually, you've found these Lapis ores on an underwater area, so therefore this is not a bug.
Lapis generates from -64 to 56 when it's not exposed to air.