Yes, you can order the needed licenses and migrate the rest, that's one possible option.
Please remember though, that CUWL licensing is not entirely based on the number of phones as DLUs were, and if any of those phones are second or third devices that are to be used by the same user, then they can assign up to 10 devices to a single user without needing any further licenses. If all 192 devices are going to separate users, then you will need 192 licenses, but it doesn't make sense to buy CUWL licenses for those devices, as UCL licenses can cover those phones at a discounted price. CUWL should usually only be purchased if they have or plan to have multiple devices per user.