It is not uncommon for a court to order spousal maintenance (often, at the stipulated request of the parties) pending a divorce.  At least in states like California.  Don't you read the fanzines, about Hollywood breakups?  For more information, see:

https://selfhelp.courts.ca.gov/spousal-support

I've seen only one "decree of legal separation," many years ago, and as I recall it was because the wife still wanted the husband to have the insurance coverage from her job.  Other reasons are to preserve pension benefits, or to avoid violation of religious beliefs.