I specialise in treating and ideally, preventing, separation anxiety in dogs.
To that end it is better that puppies and new rescue dogs have access to their owners whenever they need it, whilst they settle in, without ever having to cry or bark or howl (ie, experience distress). In reality this means dogs sleeping in bedrooms and for puppies, likely, sleeping on the bed.
This speeds up toilet training, it also gives the new owner a much clearer idea of how the dog has found the last 24 hours or so (hard = snuggly dog, easy = more independent) and its good bonding time, helps puppies learn when its time to rest, tends to result in everyone getting more and better quality sleep.
From a foundation of security and confidence, if taken at the dogs pace, you can then teach them to sleep elsewhere when the time is right if you really want to.
Personally, I can't understand why anyone would wish to share their home and life with an animal that ONLY evolved due to the close relationship between our two species.. and then enforce time away at night when theres no good reason to do so.
If you don't want your dog in the bed, fine, not everyone co-sleeps well even with their own species... but all this locking dogs in kitchens and utility rooms I really do not understand at all.