If the Bishop made it clear that people are not to visit, why are so many tradcasters telling people to go visit?
The answer is that trads no longer understand obedience to the Magisterium.
This is the obedience Catholics owe to the hierarchy
of the true Catholic Church:

Are these defiant tradcasters and visitors giving "submission of mind, intellect, and will" to their Bishop? Why not??
Are they Protestants?
Do they not understand that disobeying your Bishop is schism?

Sadly it's because VII created a false church, a straw man church, which now can be mocked, villified, defied, disobeyed, resisted, and ultimately destroyed,
traditional minded Catholics are duped into destroying the strawman church with their own disobedience.

(strawman church of Vatican II)
The disobedience of the Bishop's directives in the Sr Wilhemina case is no different than the disobedience of the Bishop's directives in the Medjugorje case.
Sadly, concilliar trads now see themselves as the arbiters of truth who do not need to obey the authority of the hierarchy
since they can (rightly) see it is not proclaiming truth
but fail to recognize that it is
a false hierarchy
of a false church
and remnant of the apostates who left the One Holy Catholic and Apostolic Church
during the Great Apostasy of Vatican II.