to make seeds, you need bees. No bees, no seeds. The "problem" is that the Meyer flower will attract any bee within half a mile. Here's a dirty little secret used by some to their advantage... lemon seeds are heavier than the fruit; so if you are selling lemons by the pound, more seeds means more money...until the quality is so bad that no one will buy the fruit.

Will blocking out pollinators impact fruit set?

Not at all; the Meyer flower does not need help from anyone or anything to make lemons.