Yes, basically that is the case.
There are few that do speak a little English. Sometimes under “Race” they may mention language ability with English – but you will often find they do not have their phone number listed. You may be able to search around for one that speaks English and has listed her phone number, but this will limit you to a pretty small sub set of the total availability.
Most will not speak English – remember this is China. Normally you just show up. It is best to have a few back ups, unless you can wait around awhile. I think the Hotel reservations may be better at booking ahead by phone. Don’t be mislead – generally you go to their hotel instead of bringing them back to your place – if that is what worries you.
Either way, just jump in and be a little flexible. It is not that difficult. Really you should not have much trouble getting laid in Hong Kong. Good luck