When we had Hollands & Mini Lops we crossed a few to Rex & Mini Rex. Generally the kits' ears sagged around 5 weeks old or so. We had the occasional kit have really nice "lop" ears (from the mini rex) but most kits had control over their ears even grown and could raise them when on alert.
I've bred a Holland to a Lionhead and of the 3 kits 2 had upright ears and 1 had 1up 1down (my avatar). In the next generation though I get a good amount of lopping. Personally I wouldn't expect much from the ears on the first generation. I've bred a Holland to a Mini and didn't get lops.
You get weak upright ears. They may just be wider based than normal or they may even partially/mostly flop especially in heat. You don't really get a good version of either ear type. Breeding the crosses should produce lops again.