Conflict: Asking for post password on filter ‘the_content’

I’ve a custom functionality for WooCommerce Coupon, where any text can be saved via WordPress editor to coupon’s custom meta. This feature also sends this text to order email. The issue is when I’m sending new order notification from admin side, instead of the text, it’s showing a password field, asking to see that text, in email. This is because I’m applying filter the_content on WordPress editor content, which is a common practise.

I checked code of Easy Custom Auto Export & found that the function tonjoo_ecae_execute is hooked to filter the_content which is internally checking post_password_required for all post type. This functions check for correct cookie, if not found it asks for password. My question is, is it necessary to add this filter for all post type or this functionality should be restricted to those post type where it is required.