All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
This is not an obligation for either of the spouses; it is permissible for them to be together in one bed, or room, or house, and it is also permissible for them to be in a separate bed, or room, or house.
What is obligatory is to give the wife her right in having sexual intercourse with her and in being just between her and other wives.
However, the scholars stated that it is better for the husband to sleep with his wife in one bed, unless he has an excuse.
An-Nawawi said in his commentary on Saheeh Muslim:
“The correct procedure is that the husband sleeps with his wife if none of them has an excuse for being alone. Being together in one bed is better. This is what the Prophet constantly did even though he constantly observed standing in night prayer as well. So the husband sleeps with his wife, and when he wishes to get up for worship (or otherwise), he gets up and leaves her. Thus, he fulfills his worship and observes her recommended right, especially if he knows that this (sleeping with him in the same bed) is important to her.”
The statement of Ibn Al-Jawzi which you mentioned is found in Sayd Al-Khaatir, and he did not give any justification for it, but some scholars said that this is useful in bringing affection, because always being side by side may lead to boredom, and if they are separate, then this may generate longing for each other. However, it may lead to the opposite, especially if the woman loves her husband and her heart is attached to him. So it is more appropriate for the husband and wife to sleep together in one bed as much as possible as we have mentioned at the beginning.
Allah knows best.