I hate to say it, but I think your greater concern would be if any of these resorts are open in that timeframe. There's a lot of unknowns right now. Assuming the closures extend into May and are over by the time you go, I personally I don't expect anything to be super crowded at the World in the beginning. The economic fallout will be felt for far longer and a lot of people who otherwise would be packing those pools may not have the disposable income for a Disney vacation much less at a Deluxe resort.
FWIW, even if the lava pool at the Poly is crowded, the Oasis pool almost never is, and I prefer that one anyway. The hot tub is better and the Oasis grill is there and a very underrated QS option.