This isn't an assault on 'Christianity'. Its an assault on Bible studies led by state employees on state property.
It's an assault on a perso being allowed to do things which might make them "unapproachable" if they are a public employee.
And what do the powers-that-be think makes a person unapproachable? The only thing they seem to have banned is overt acts of christianity.
If they force female RAs to wear Burkas because otherwise muslims might find them unapproachable, I'll believe this isn't an assault on christianity.