All the time you are complain about something what is out of main game and out of control of devs.
Using widget settings in game you can hide notifications. Since CCP devs maintain EVE client, you have option to not see notifications. They are anyway sent to your account because cluster need do this to work correct.
They are not totally offline probable because server (cluster to be exact) to maintain its data or something similar. Cant tell exact why it work this way since im not EVE dev.
TL;DR If you forget about this, EVE is MMO. All data must be sync by cluster and send to all device connected (players, API etc.) in same amount and way they are sent. Software that receives and interpret that data (EVE client) can bypass some information and don’t display them on HUD.
Ps. This is only my private explanation as person who has some experience with games, computers and network but my be incorrect since I don’t have any data from CCP.