nice feature, but is there a reason why we don't use the other parameters of ChatInviteLink here too? Similar to how we do in send/edit_location

TBH, I hadn't really thought about it, but interesting idea! you'd do something like e.g.

if isinstance(invite_link, ChatInviteLink):
    expire_date = expire_date or  invite_link.expire_date

? That could work. If we want to allow users to e.g. delete the expire_data, we'd have to maybe do something like

def edit_chat_link(…, expire_date = DEFAULT_NONE):
    if isinstance(invite_link, ChatInviteLink):
         expire_date = expire_date or invite_link.expire_date
    expire_data = DefaultValue.get_value(expire_date)

such that edit_chat_link(chat_link_instance, expire_date=None) allows to explicitly set expire_date to None.
And we'd have to mind that one could want to override member_limit with creates_join_request and vice versa.

At first glance, I'm not sure if the added convenience is worth the added complexity of the method. What do you think?