The part in the article where it states that LvG has ordered the no. 7 shirt to be reserved is the part which broke my suspension of disbelief.
It's absurd to think that LvG who had just joined us, is well versed with the value & history of the no.7 jersey enough to reserve it specifically for Vidal.
To be fair, the United #7 jersey is not exactly some obscure bit of United history. I don't see any reason why LvG could not be aware of that jersey and the place it holds in the club's history.