I understood your query, Unfortunately, at this stage, I don't have any Judgement regarding such case or what stand Supreme Court has taken in such cases
If University is formed by Act of state legislature or parliament then degree will be valid
But such cases regarding higher academic study always there remain some or other ambiguity.
Take for eg. if you do graduation from open university without doing 12th , then you are qualified for exam of Public Commission, like Maharashtra Public Service Commission, even Union Public Service commission I suppose allow but if you want to do LLB then not completing 12th and getting graduation degree from open university is not considered valid qualification for admission for +3 LLB degree after graduation
So such cases and your problem have to be determined case to case and to specific problem now onward means no one can give blanket order that it will work and will be valid just like traditional universities in India , Means if you have Mumbai Univiersity degree or Pune University degree no issue of even thinking on that line but regarding open university all have to think and see to it that it fits in rules etc. or latest judgement regarding them