Does the manufacturers WOT recommendation change when changing prop pitch?

No, the engine needs to be able to make the manufacturer's spec'd WOT range, or minimum, as the case may be, to prevent bogging, minimize problems and repairs and to maximize engine life.

Prop blade count, diameter, pitch, rake and cup need to be configured to get to the WOT spec.

JPK is correct. The engine needs to be able to run at the recommended WOT RPM when on plane

loaded and trimmed properly. The engine HP is "fixed" so the variable to change WOT RPM's is the prop.

Increasing pitch (higher number) loads the engine more decreasing RPM's.

Decreasing pitch allows RPM's to increase. You can expect 200-300 RPM change with every "step" in

pitch number eg - If it runs 4500 rpm's with a 19 pitch prop, you can expect it to increase to 47-4800

by stepping down to a 17 pitch.

Lowering the pitch also increases acceleration out of the hole.

Choosing SS or aluminum, 3 or more blade, rake etc is optimal, but for the average boater isn't necessary.

Choose a quality aluminum prop pitched so you get the recommended RPM's and go have fun.

ETA - The Mfg's RPM range doesn't change with prop pitch. You change the pitch to attain Mfg's RPM range.