More prewar cruisers improve American scouting

Would building more American cruisers before the war make this discovery more plausible?

Yes; more cruisers would add scouting and escort capacity, and the Washington treaty did not initially impose a cumulative cruiser limit.

More American cruisers would make a discovery like this more plausible and improve the fleet generally. The Washington Naval Treaty did not initially impose a cumulative cruiser limit, so the United States had room to expand this force without changing the treaty. Guns fitted to Lexington and Saratoga could instead have armed additional heavy cruisers. That choice would leave the carriers with less topweight and more room for aircraft while adding useful scouts and escorts.