Originally 7 days struck me as the kind of compromise a state would reach when trying to balance between the actual infection risk, and what percentage of the workforce would be absent according to various models. I could sort of see the rationale behind it when they were mostly going for the 'anyone with any symptoms vaguely similar to Covid-19 should self-isolate'. But its not a number of days driven purely by medical knowledge, its a compromise. And then, just like with decisions to describe certain kinds of contacts as close only if they lasted at least 15 minutes, the arbitrary numbers we have chosen for a specific reason then end up getting treated as some kind of fundamental truth, rules the virus sticks to. When obviously it doesnt care about our rules and definitions. So its bloody stupid to take the 7 day value, which was a compromise for a particular situation, and then treat it as though this is the amount of time that actually confirmed cases who tested positive should isolate for, and that any longer is unnecessary.
So yeah, I would say its not wise. Its possible that they can get away with such things without it making a really large difference because so much of the transmission between people actually tends to happen earlier, in which case it would be another numbers game, another factor that went into the earlier compromise calculation. But its not what you would choose to do if you were actually trying to minimise the risk for every single person, its the sort of thing you might get away with if only looking at the very largest picture, and trying to dodge the very scariest scenarios with their terrible orders of magnitude. If tens of thousands of lives lost now matters, but hundreds still dont, all sorts of sloppy decisions can be gotten away with in that numbers game, and it is tempting for me to put the 7 days thing in that camp