I think they've figured out that if they call in the middle of the night, people will answer without screening, thinking it must be some dire emergency call from a loved one. This lets them know the number is verified as working, which is useful information for scammers. The B/S about being "removed from our list" is bogus. I got this call two nights in a row, from this number and a completely different one. Same message. One at 2:25am and the other at 4:15am.
They called at 2:30 am. We had a dear friend in the hospital and I thought it might be about them. I fell down the stairs rushing to answer this. The next day the number was "not working"