I have noticed that many owners complain about scouting imperfections. I suppose if one of them were to challenge me, I would say this kind of customization would allow the WIS crew to make scouting perfect, since each league would then be allowed to choose its own level of imperfection. I don't see what's fun about the idea of perfect scouting, but to each his own.
I think it would be fun because it could be used to undermine the potential for superteams and simultaneously subvert the incentives for tanking. For those players who are good enough to have created a dynastic superteam under the present setup, it would offer these owners of estimable skill a new and hopefully entertaining challenge. What choices would you make if say your scouting might indicate that a player is MLB material, but can't definitively tell you if he's actually quite good? What do you bid on an IFA who you can see is good, but may or may not be great? An owner knows what attribute he (or she) most values when he knows his scouting can accurately convey all attributes in advance. But, now the question will be raised, which attribute can I least afford my scout to be wrong about? The whole decision making process is not categorically changed, but it becomes more subtle. Failure is easier, prolonged success still possible but harder and more rewarding than ever.
I like the question you raise about potential alterations and transitions. It's a good question. Perhaps it would be best to have any change in the setting require the approval of the owners. Or, perhaps the setting is simply declared to be permanent disallowing any future alterations.