By saying “your DM might get buried under the avalanche of work-related DMs by Monday” indicates an interesting combination of awareness and a lack of awareness that I find both baffling and too common.
We detached this subthread from https://news.ycombinator.com/item?id=20585666 and marked it off-topic.
I'll assume good faith and respond to what I think your argument probably is: Maintaining separate accounts just to prevent phishing is basically security through obscurity. All you're doing is adding some level of implicit trust to messages you receive on your "work account", which isn't actually secret and can probably be discovered by a sufficiently motivated person.
He is openly admitting to being vulnerable to a type of denial of service attack. If he is flooded with communications, he would be delayed in reading other important communications.
I do not advocate security through obscurity, which is security theatre. I also think Discord should open source how various systems operate, particularly law enforcement interfaces, as I do not believe law enforcement are any better.