There's no fundamental reason why you couldn't write an abstraction around the page table that the rust borrow checker understands.
The rust borrow checker works on the principle of ensuring that if you have a unique pointer (&mut) to something, nothing else can access it. If you have a shared pointer (&) to something, nothing else is mutating it except where internal mutability is explicitly marked (UnsafeCell, and abstractions using UnsafeCell such as Cell, RefCell, Mutex, RwLock, and so on).
To mutate a page table entry you would need an &mut reference to it, to access a page you would need an & reference to the page table entry (from the &PageTableEntry you would get a &[u8] pointing to the data which the borrow checker would guarantee you drop before you drop the &PageTableEntry before anything mutates the PageTableEntry).
The rust borrow checker works on the principle of ensuring that if you have a unique pointer (&mut) to something, nothing else can access it. If you have a shared pointer (&) to something, nothing else is mutating it except where internal mutability is explicitly marked (UnsafeCell, and abstractions using UnsafeCell such as Cell, RefCell, Mutex, RwLock, and so on).
To mutate a page table entry you would need an &mut reference to it, to access a page you would need an & reference to the page table entry (from the &PageTableEntry you would get a &[u8] pointing to the data which the borrow checker would guarantee you drop before you drop the &PageTableEntry before anything mutates the PageTableEntry).