Hi,

To make a page invisible after a specific date in Odoo 16, you can create a custom module and use the date_deadline field in the model to set the expiration date. You can then compare the date_deadline with the create_date of the record to check if the page should be visible or not.

In your model add fields, 
date_deadline = fields.Date('Expiration Date')
is_visible = fields.Boolean('Is Visible', compute='_compute_is_visible')

@api.depends('create_date', 'date_deadline')
def _compute_is_visible(self):
for page in self:
if not page.date_deadline:
page.is_visible = True
else:
page.is_visible = fields.Date.today() <= page.date_deadline

Now you can add this field is_invisible in attrs for your page 

 //your fields inside page

Hope this will help you
Thanks