I don't see that every happening, maybe a select few multiplayer games could do it as a feature or something but as a system wide setting I don't see it.
I feel that Sony's approach is superior given Valve axed Family Sharing support in Offline Mode. Simultaneous access with PSN drops throwing a spanner into the works, as annoying as that can be, strikes me as fairer than single-user access with the secondary user having a short "grace period" to exit when the library owner runs any game. Ideally, Family Sharing would be an amalgamation of the two: multiple users can access the one library concurrently, save for running the same game at the same time, with the account owner preference system being left intact (e.g. two people could be playing two different games, but the account owner running, say, CS:GO results in Secondary User #2. who's playing CS:GO, being slapped with the aforementioned grace period). But at this point, I've begun to give up hope of Valve going out of its way to improve the system.