As NW plat I got EUAed at the 5-day window a couple weeks ago for flights I'd purchased in bargain-basement L class. I also got EUAed on a flight in U class a few weeks before that.

I think EUA is running as usual, but that they're allocating very few seats to it except on relatively empty flights. On flights that are fairly full, I think they're holding the majority of FC seats back in the hopes of selling last-minute Z fares that are comparable in price to the walkup coach fares on other carriers (and often cheaper than CO's own H fares).