Maloof had nothing to do with Vivian Maier's storage lockers.
Their contents were bought by a company named RPN sales who were in the business of buying things from storage locker sales and then turning them around at a profit.
RPN bought everything for $260.00, broke it all up into smaller lots and then sold those lots from their premises for a total of about $20,000.00. Maloof was actively involved at that time in eBay and similar sales of vernacular photography. He bought one large lot with an absentee bid, liked what he saw and started tracking down other purchasers, some of whom re-sold to him.
And as for probate of intestate (meaning no valid Will, or a Will that fails to deal with the entire estate) estates, while the laws vary with jurisdiction, most that sprung from the traditional English roots (which most of the US and Canada did) built a whole system to try to prevent estates from going to the King/the Government.
The challenge with an intestacy is that the applicable law sets out a set of rules specifying who gets what and how much. Those rules divide an estate amongst the relatives of the deceased based on how close those relatives are in the deceased's family tree - a so called tree of consanguinity.
I'll discuss intestacy a bit to try to give a sense of the complexity.
Using my jurisdiction as an example, simple families are easy to deal with - surviving spouses or spouses and kids share in everything, according to a formula.
If there are no surviving spouses or kids, then surviving parents share.
If there are no surviving spouses, kids or parents, then surviving siblings share, provided that if a sibling pre-deceased leaving "issue", then that "issue" shares their parent's share, divided per stirpes (the first use of Latin here, but it becomes very common when you start researching intestate succession).
"Issue" include children, grand-children, great grand-children, etc. - they all share in that per stirpes distribution.
If there are no surviving spouses, children, parents, siblings or issue of siblings, then attention turns to the siblings of the parents (uncles and aunts), but if they pre-deceased than the shares that would other wise have gone to those siblings are divided between their issue per stirpes. So now we are getting into the problem of identifying various distant cousins of various degrees. And because the division is amongst issue, you can have shares split up among people over several generations, including infants whose entitlements cannot be finalized until they attain an appropriate age of majority.
Vivian Maier had lots of distant relatives, but she had little or no contact with any of them in her later years. Many are/were in France, but they are/were in many other parts of the world. At the time of her death, none of those relatives were close enough to her in the tree of consanguinity to permit an easy and simple resolution of her estate. And it doesn't appear that there was anyone around who had all the necessary family information neatly organized in a form that would help resolve the problem.