NEW YORK — April, a poet famously said, is the cruelest month. But on Broadway, it’s the month of amazing, unbridled optimism. Between April 1 and April 26, no fewer than 16 Broadway shows are opening, an average of more than one red carpet and selfie station every two days. It’s the busiest April ever. And this with the COVID-19 crisis not entirely in the rearview mirror. Is this a reflection of massive new demand? Not really. There is certainly evidence that Broadway has staged a healthy recovery in recent weeks, as tourists have returned to Midtown and New Yorkers have felt more comfortable…