Meconopsis paniculata is monocarpic - it blooms once and that's it. It's a bit of gamble as to whether cutting the bloom forming now will result in a flower next season or not - I've seen it happen with some other monocarpic meconopsis, while others don't produce (late season flowering is not uncommon). You could just let it flower now and collect the seed or allow it to self-seed. Guess it depends on how much of a gambling nature you have :-)

The difference between "biennial" and "monocarpic" is that monocarpic plants may take more than two years to reach flowering size. As with biennials, flowering and seed production do tend to be fatal.

Thank you for your advice, I've decided to let it flower and hope to gather seeds. It seemed the least risky choice from what you say.