I'm no expert on the subject but the Osprey book on WW2 Italian forces in Africa states that the uniforms had changed very little since 1936, the only significant difference being the gradual replacement of the distinctive red tabusc by the less glamourous bustina cap, much to the chagrin of the askaris who apparently tried to hold on to their tabuscs as much as they could. I see no reason why the Empress askaris could not be used for the 1941 campaign, especially since the chaotic state of Italian logistics in Eritrea and the isolated nature of the East African theater of operations meant that old stocks of uniforms and equipment continued to be used for want of new supplies.
Off the cuff, I don't think the Eritreans saw action in Lybia as the Italians had distinct native divisions of Lybian askaris there, but more knowledgeable people may prove me wrong on that.