I did the same thing. I have a lot of old neighborhood data from previous installations that I wanted to keep using. I had migrated game data before without any problems, as I had changed computers twice since The Sims 2 was originally released. However, I could not successfully transfer the files from my original installations to the Ultimate Collection. You copied the contents of the neighborhood folder from your original Sims 2 folder into the corresponding folder in the Ultimate Collection directly, correct? And this worked without any problems? When I attempted to do the same thing, I got the same result as this:
The neighborhood I tried to copy into Ultimate Collection was a default neighborhood, so I simply replaced the file. When I ran the game, that exact neighborhood was completely missing.
I was able to copy the folders over without any problems. Did you make sure to delete or rename the files with the same names in the Sims 2 Ultimate Collection > Neighborhoods folder?
