I have booked a 2 bedroom unit at quite a few resorts over the years that were lock-off units when we got in. They were not advertised or described as a lock off. The 2 bedroom units Vacation Village Resorts are one example. Sometimes you can search for a floorplan of the units at a particular resort to see if they have lock-offs. I can usually tell if it might be a lock-off when I book a 2 bedroom that has an occupancy of 8 or more, although one time it turned out that there were 2 queen sized beds in one of the bedrooms and it wasn't a lock-off. Another time in Williamsburg (Powhatan?) there was a loft with twin beds in addition to the 2 bedrooms. Both situations worked out well for our 3 pre-teen & teen kids, each of whom would not share a bed with anybody!
We like lock-offs when travelling with our adult kids, our older (early 20s) grandkids or another couple. They provide a lot of privacy and the extra fridge and TVs come in handy.
~Diane